index of transportation measure quantification efforts ... · advantages of methodology...
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Transportation Control Measures: Methodology Matrix
TransportationMeasure Methodology
Advantagesof Methodology
Disadvantagesof Methodology Report Description Advantages of Study
Disadvantagesof Study Factors Analyzed
AlternativeCommutePrograms
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actual trans-portation measure,such as reactionsto expect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from theTCM implementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Provides compre-hensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing variousTCM measures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specific TCMevaluation method
Estimates VT, VMT, &emission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
dac
AlternativeTransporta-tion-FriendlyWorkplace
Travel demand/mode choicemodel
Somewhat appli-cable to multipleregions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Level of serviceprovided byemployer:information,matching services,preferential parking,ride home programs
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TransportationMeasure Methodology
Advantagesof Methodology
Disadvantagesof Methodology Report Description Advantages of Study
Disadvantagesof Study Factors Analyzed
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AlternativeTransporta-tion-FriendlyWorkplace(cont.)
Travel demand/mode choicemodel (cont.)
"A Survey and Analysisof EmployeeResponses toEmployer-SponsoredTrip ReductionIncentive Programs." Schreffler, Eric N., andMortero, Jose.COMSIS Corp.California AirResources Board,February 1994. Contract No. A983-187.
Describes resultsof new surveydata regardingemployee travelbehavior; usesmode choice andtravel demandmodel to predictimpacts of certainemployer-basedtransportationmeasures
Clearly explains theprocess that was used: survey data acquisition,mode choice computa-tion, and TCM effective-ness model use
Data requirements aremore readily availablethan other models
User-friendly model isavailable for outside use;users guide is alsoavailable
Survey links incentivesdirectly to impacts ontravel behaviorModel includes anawareness sub-modelthat simulates how manypeople know about thepossible transportationmeasures available tothem
Does not accuratelyaddress trip-chainingand VMT reductions(only trips)
Household conditionsare not extensivelyaccounted for
Cost-effectivenesswas not calculated
Employer-levelanalyses only, withfocus upon incentiveTCMs
Guaranteed ridehome
Company vanpools
Preferential parking
Parking fees forridesharers
Carpool subsidies &transportationallowances
dac
"Selection andEvaluation of TravelDemand ManagementMeasures." Taylor,Christopher J., et al. TRB Paper 971114,January 1997.
Uses TravelDemandEvaluation Modeldeveloped byCOMSIS toevaluate theimpact oftransportationmeasures onmode choice andVT for theSyracuse, NYmetropolitan area
Uses journey-to-workcensus data to developestimates of zone-to-zone travel
Evaluates both area-wideprograms and employer-based programs
Assesses revenuegeneration potential andtransit subsidies
Sufficiently detailedjourney-to-workcensus data may notbe available for allcities: Syracuse hasthis data available dueto a pilot program
Requires assumingsome estimates ofeffectiveness
Does not quantifyemissions reductions
Transit fare levelsand travel time
HOV lane timesavings
Parking costs
Employer transitencouragement level
dac
TransportationMeasure Methodology
Advantagesof Methodology
Disadvantagesof Methodology Report Description Advantages of Study
Disadvantagesof Study Factors Analyzed
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AlternativeTransporta-tion-FriendlyWorkplace(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel employedto model the VT,VMT, and emis-sion reductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationuses standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
Empiricalanalysis of theimpacts ofpersonalpreference andworkplaceconditions onmode choice
Somewhatapplicable tomultiple regions(but likely to beinfluenced heavilyby local factors ofthe study area)
Can be replicated(at moderate tohigh cost)
Does not requireextensivecomputer model
Uses actualsurvey data
Requires large datacollection process togenerate statisticallysignificant results
Personal preferenceand workplaceconditions difficult toimpact throughpublic policy
"The Influence ofEmployer RidesharingPrograms on EmployeeMode Choice." Ferguson, Erik. Transportation, vol 17,1990.
Analyzesaggregate-leveldata compiled bya large SouthernCalifornia regionalridesharingagency; assessesimpact ofemployercharacteristics onemployee modesplit
Analyzes a large data setcomprising almost 10%of Los Angeles areaworkforce
Utilizing existing agencydatabase is a cost-effective approach
Less accurate thandisaggregated (employeeby employee) data
Includes cost-effectiveness estimations
Some findings mayhave been contra-dicted by more recentstudies (e.g., studyfinds that large corp-orations have bettersuccess with rideshareprograms)
Aging data source: 1985 survey data
Los Angeles areafactors may beuncharacteristic ofother regions, soresults may not beapplicable elsewhere
Employer-derived datawas acquired usingdifferent methods
No estimates ofemissions impacts
Level of employereffort to encourageridesharing
Size of firm
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TransportationMeasure Methodology
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AlternativeTransporta-tion-FriendlyWorkplace(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhat appli-cable to multipleregions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
Not described dac
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specific TCMindividually; programsof multiple TCMs areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancy assumpt-ions for each modechoice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
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AlternativeTransporta-tion-FriendlyWorkplace(cont.)
Employer TDMcost-effectivenessmodel
Estimatesreduction in andcosts of daily tripsand peak periodtrips
Aids employerdetermination ofcost-effectivenessof TDM measuresfor their particularworksite
Results may varywidely from oneemployer to the next
Many inputs may bedifficult foremployers orplanners to quantify
"TransportationDemand ManagementCost-EffectivenessModel for SuburbanEmployers." Dagang,Deborah A. JHK &Associates. InTransportationResearch Record 1404.
Reports on thedevelopment of amodel toindividuallyevaluate the cost-effectiveness of15 differentemployer-basedTDM measures insuburban settings
Focus on suburbanemployers reflectsdifferent travel-relatedcharacteristics ofsuburban and urbanareas
Spreadsheet-basedmodel is user-friendlyand readily accessible foruse at the site-specificlevel; model makessensitivity analysisrelatively simple
Eight transportationenvironments weredefined to representvarious combinations oftransportation servicecharacteristics
For employers withoutaccess to entire range ofdata necessary tooperate model, defaultvalues are included
Most employerssurveyed to developmodel were unable toprovide detailed costinformation on theTDM measures theyhad implemented
Does not calculateemissions directly
Potential for regionalbias, as model wasdeveloped in partbased on a survey ofsuburban SanFrancisco Bay Areaemployers; model alsoused the SCAQMDRegulation XV andPima Association ofGovernments TravelReduction Programemployer plandatabases
Only some TDMsincluded in modelprovide for estimatesof VT reductions
Use of default valuescould diminishesaccuracy of estimatesfor some users
Suburban employer-based TDMmeasures
Daily trips and peakperiod trips
Costs and cost-effectiveness
dkp
TransportationMeasure Methodology
Advantagesof Methodology
Disadvantagesof Methodology Report Description Advantages of Study
Disadvantagesof Study Factors Analyzed
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AlternativeTransporta-tion-FriendlyWorkplace(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningand implementa-tion methods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from theTCM implementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specific TCMevaluation method
Estimates VT, VMT, &emission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
dac
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of transportation measureoptions, as well astechnology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
dac
"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relativeeffectiveness ofvarioustransportationmeasure programs
Implementationmechanisms
dac
TransportationMeasure Methodology
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Disadvantagesof Methodology Report Description Advantages of Study
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AlternativeTransporta-tion-FriendlyWorkplace(cont.)
Comparisonand analysis ofother studies(cont.)
"ManagingTransportationDemand: MarketsVersus Mandates." Giuliano, Genevieve,and Martin Wachs. Reason Foundation. Policy Insight No. 142,September 1992.
Comparescongestion pricingwith RegulationXV for theSouthernCalifornia area;describes prosand cons of eachmeasure anddiscussesimplications
Provides typology oftransportation measuresand identifieseffectiveness andcommon barriers toimplementation
Simple side-by-sidecomparison of VMTreduction and cost-effectiveness for eachtransportation measure
Makes policy recom-mendations to improveeach transportationmeasure
Provides little detailabout logistics ofimplementing thepolicy recommenda-tions
Does not quantifyemission reductions
Direct vs. indirectimplementation
Market-based vs.performance-basedimplementation
Efficiency and equityconsiderations
dac
"The Equity and CostEffectiveness ofEmployee CommuteOptions Programs." Farkas, Z. Andrew. Morgan StateUniversity. TRB960078, January 1996.
Analyzes theresults of surveysand transportationmeasuremodeling studiesperformed for theBaltimore andPhiladelphiaregions
Shows different methodsof using the same model: Travel DemandEvaluation Modeldeveloped by COMSIS
Provides a discussion ofsocial equityconsiderations based ona survey of the tworegions
Philadelphia modelingassumed averagevehicle ridershiptargets were reachedand results are onlyapplicable relative toeach scenario
Baltimore modeling didnot estimate emissionsreductions
Rideshare promotionlevel
Parking charge level
Transit subsidylevels
Work scheduleflexibility
dac
Bicycles Travel demand/mode choicemodel
Somewhat appli-cable to multipleregions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Bicycle mode share dac
TransportationMeasure Methodology
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Disadvantagesof Methodology Report Description Advantages of Study
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Bicycles(cont)
Parking supplyand demandmodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires computermodel
Potentially high costto use
"Air Quality Offsets forParking." Loudon,William, et al. InTransportationResearch Record 1232,1992.
Develops anduses parkingsupply model fordowntownPortland toestimate COemissions
Uses observed price andtravel time sensitivities
Uses proven models oftravel behavior
Incorporates integratedCO emissions model
Requires parkingdatabase: number ofspaces, location, type,use patterns
Requires traveldatabase: time ofarrival, travel & workmode split
Travel time & cost dac
Statisticalanalysis of theimpacts of landusecharacteristicsand TDMstrategies onmode choice
Identifies land useand urban designcharacteristicsthat are supportiveof walk/bike modechoice.
Standard analysisof variance usingprinciple compo-nents allowsexamination of theeffects of land useand TDMincentivestrategies onmode choiceindividually and incombination.
Results transfer-able to otherurban areas interms of relativeranking ofimportance of theland use and TDMfactors analyzed.
Precise causalityand individualimpacts of factorssuch as transitavailability or urbandensity on modechoice cannot bemeasured due tolimitations of thedatabase
Potential for need toconduct extensivefield research todetermine land usecharacteristics ateach sample worksite.
Cannot be used todetermine land useand urban designcharacteristics'impact on a specificmode choice
"The Effects of LandUse and TravelDemand ManagementStrategies onCommuting Behavior: Final Report." Prepared by CambridgeSystematics, Inc. andDeakin, Harvey,Skabardonis, Inc. forthe U.S. Department ofTransportation,November 1994.
Develops anintegrateddatabase of landusecharacteristicsand traveldemandmanagement(TDM) strategies(for a sample ofemploymentlocations) todetermine thecombined impactsof TDM programs,land use, andurban design onemployee travelbehavior.
Added land use and siteinformation from fieldobservation to the"Regulation XV" datasetof the South Coast AirQuality ManagementDistrict (which includedaggregate employeetravel characteristics andemployer incentiveprograms)
Study conducted inLos Angeles County,and thus may be lessapplicable in moredense urban areaswith factors such ashigher average densityand transit service.
Share of work tripsmade by bicycle as apercentage of the totaltrips in the data set issmall, makingidentification of worksite characteristicsthat encourageutilization of bikesdifficult.
Did not addressresidential trip end ofcommute, middaytravel, or trip chainingas factors whichinfluence mode choice
To simplify acomplicated datacollection process,somewhat arbitraryindicators were usedfor assessment of asite's urban designand land usecharacteristics.
Land use and urbandesign of worksite
TDM incentivestrategies
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Bicycles(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
Not described dac
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specific TCMindividually; programsof multiple TCMs areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
dac
Sample surveyof customertravel patternsand prefer-ences atshoppingcenters
Somewhatapplicable tomultiple regions(but influenced bylocal factors of thestudy area)
Does not requirean extensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
Moderate to highcost
"Analysis of IndirectSource Trip Activity:Regional ShoppingCenters." JHK &Associates/ K.T.Analytics/ California AirResources Board.November 1993, ARB-R-94/510.
Surveyedcustomers ofregional shoppingcenters todeterminepotential impactof various travelreductionmeasures
Uses actual survey data(including customerdemographic and statedpreference data)
Developed calculationmethodologies specific toeach trip reductionmeasure, using site-specific data
Compares data betweenshopping centers indifferent land-use types
Assumptions arerequired to translatestated preference datato expected outcome
Does not quantifyemission reductions
Distance of travel forconsumers
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Bicycles(cont.)
Cross-sectionalanalysis ofbicycle facilities
Low cost toperform (ifdatabase isavailable)
Requiresconsiderabledatabase
Study results do notnecessarily apply toother regions
"If You Build Them,Commuters Will UseThem: Cross-sectionalAnalysis of Commutersand Bicycle Facilities." Nelson, Arthur C., andDavid Allen. GeorgiaInstitute of Technology. TRB 970132, January1997.
Analyzed adatabase of 18US cities todetermine whichfactors mostinfluenceincreased bicycleuse
Identifies some importantfactors affecting bicycleuse, as well as severalthat do not affect bicycleuse
Does not assess manyfactors that couldinfluence bicycle use
Cannot predicteffectiveness of newfacilities
Does not performbefore-and-afteranalysis of actual in-use facilities
Requires largerdatabase to performmore rigorous analysis
Bikeway miles per100,000 population
Terrain type
Annual rain days
Percent students
Mean high-temperature
dac
Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasure effective-ness at low cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"Evaluating theEffectiveness ofTransportation ControlMeasures for San LuisObispo County,California." Morrow,David D., San LuisObispo Air PollutionControl District, 1992.
Develops anduses a calculationmethodology forestimating the tripreduction and airquality benefits ofbicycle facilityimprovements inSan Luis OpispoCounty
Methodologies aredeveloped specifically forthe bicycle facilityimprovement program
Explains calculationprocess in detail
Requires extensive,region-specific infor-mation to accuratelyestimate benefits andeffectiveness of theprogram
Assumes a level ofprogram participation(as required by themeasure)
Many; not specified dac
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Bicycles(cont.)
Sketchplanning (cont.)
"Simple Methodologiesfor Quantifying VT andVMT Reductions fromTransportation Controland Growth Manage-ment Measures forDeveloping Local TripReduction Ordinances." Evans, V. and D.Morrow. SonomaTechnology, Inc. Air &Waste ManagementAssoc. 1993.
Describesdevelopment ofsimple method-ologies forquantifyingreductions invehicle trips (VT)and vehicle milestraveled (VMT)from TCMs, foruse in a planning-level context;developedoriginally for theSouth Coast AirBasin
Methods to quantify VTand VMT reductions fromTCMs were based uponrelatively simple methodsfor estimating emissionsand individual TCMeffectiveness developedprior to this report for theSouth Coast AQMD
Performance-basedapproach was developedrather than usemandated transportationperformance standards
Actual experience dataused as much aspossible: estimated tripreduction levels fromeach TCM was collectedfrom other studies, andplanning-level analysisuses site-specific datainputs, thus offeringincreased precision inemissions estimates
Ranges in VT reductionsestimates address theinteractive impacts of theapplication of multipletransportation measures
Equivalency factor usedto convert VMT to VT canaccount for region-specific average triplengths
Expected reductions inVT and VMT fromTCMs were estimatedbased upon a generalsurvey, so for aparticular locationdifferent assumptionsmay be needed
Applicability to otherregions outsideCalifornia limited byreport's use oftransportation dataand emissions factorsin the analysis whichwere quantified usingBURDEN and EMFACruns for 1994Does not incorporateany consideration ofcost-effectiveness
Employee partici-pation (percentageand frequency)
Trip length
Bike parking facilities
Existence/extent ofbike path system
Existence of showerfacilities
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Bicycles(cont.)
Sketchplanning (cont.)
"Evaluating Travel andAir Quality Cost-Effectiveness ofTransportation DemandManagement Projects." Schreffler, Eric N.,Therese Costa, andCarl B. Moyer. InTransportationResearch Record 1520,1996.
Describes simplemethodologiesused to evaluateprojects fundedby the AB 2766vehicleregistration feeprogram inSouthernCalifornia
Methodology can beused to evaluate priorprojects or proposedfuture projects
Uses available EMFACemission rates tocalculate ROG, PM10,NOx, and CO
Study developsstandardized worksheetto evaluate projects
Study points outdrawbacks of self-reported project results
Methodology relies onparticipation dataprovided by projectproponents, whichmay not always beunbiased
EMFAC7E factors areCalifornia-specific
Trips reduced
Trip length
Prior travel mode
drl
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningand implementa-tion methods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from theTCM implementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing variousTCM measures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specific TCMevaluation method
Estimates VT, VMT, &emission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
dac
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Bicycles(cont.)
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures, Transport-ation Technologies,and Pricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of transportation measureoptions, as well astechnology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
dac
"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relative effective-ness of varioustransportationmeasure programs
Implementationmechanisms
dac
Clean FuelFleets
Parking supplyand demandmodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires computermodel
Potentially high costto use
"Air Quality Offsets forParking." Loudon,William, et al. InTransportationResearch Record 1232,1992.
Develops anduses parkingsupply model fordowntownPortland, Oregonto estimate COemissions
Uses observed price andtravel time sensitivities
Uses proven models oftravel behavior
Incorporates integratedCO emissions model
Requires parkingdatabase: number ofspaces, location, type,use patterns
Requires traveldatabase: time ofarrival, trave & workmode split
Vehicle emissionsrates
Number ofalternative fueledvehicles
dac
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Clean FuelFleets (cont.)
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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CompressedWork Week/Flex Time
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
4/40, 3/36, and 9/80work weeks
Participation levels
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CompressedWork Week/Flex Time(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasure AnalysisProcedures." Austin,Barbara S., et al. Systems ApplicationsInternational/CaliforniaAir Resources Board.Nov 1991. SYSAPP-91/141.
Describes adevelopedtransportationdemand modeland explicitlydiscusses thecalculationmethodologyused for severaltransportationmeasures
Model quantifies keysecondary effects ofTCMs (e.g. newcarpooling programs mayattract transit ridersrather than SOV riders)
Presents all the primaryequations and variablesused to calculate theeffects of TCMs
Contains a step-by-stepprocess for evaluatingpackages of TCMs
Explains multi-attributeanalyses as applied tomultiple TCM packages
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient;participation level datais required; basecases need to matchreal conditions
Model does not coverall TCMs, but can bemodified to do so
Temporal treatment islimited to on-peak/off-peak, no spatialtreatment
Emissions calculationsare not explicitlydescribed in the samefashion as traveleffects
Participation levels
Potential shift incommute time of day
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"Selection andEvaluation of TravelDemand ManagementMeasures." Taylor,Christopher J., et al. January, 1997. TRB971114.
Uses TravelDemandEvaluation Modeldeveloped byCOMSIS toevaluate theimpact oftransportationmeasures onmode choice andVT for theSyracuse, NYmetropolitan area
Uses journey-to-workcensus data to developestimates of zone-to-zone travel
Evaluates both area-wideprograms and employer-based programs
Assesses revenuegeneration potential andtransit subsidies
Sufficiently detailedjourney-to-workcensus data may notbe available for allcities: Syracuse hasthis data available dueto a pilot program
Requires assumingsome estimates ofeffectiveness
Does not quantifyemissions reductions
Transit fare levelsand travel time
HOV lane timesavings
Parking costs
Employer transitencouragement level
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CompressedWork Week/Flex Time(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel employedto model VT,VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuse standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
Parking supplyand demandmodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires computermodel
Potentially high costto use
"Air Quality Offsets forParking." Loudon,William, et al. InTransportationResearch Record 1232,1992.
Develops anduses parkingsupply model fordowntownPortland toestimate COemissions
Uses observed price andtravel time sensitivities
Uses proven models oftravel behavior
Incorporates integratedCO emissions model
Requires parkingdatabase: number ofspaces, location, type,use patterns
Requires traveldatabase: time ofarrival, trave & workmode split
Time of arrival (indowntown area)
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CompressedWork Week/Flex Time(cont.)
Statisticalanalysis of theimpacts of landuse character-istics and TDMstrategies onmode choice
Use of PrincipleComponentsAnalysisgeneratedcompositevariables (groupsof land usecharacteristicswith similarimpacts)
Standard analysisof variance usingprinciplecomponentsallowedexamination of theeffects of land useand TDMincentivestrategies onmode choiceindividually and incombination.
Resultstransferable toother urban areasin terms of relativeranking ofimportance of theland use and TDMfactors analyzed.
Precise causalityand individualimpacts of factorssuch as transitavailability or urbandensity on modechoice cannot bemeasured due tolimitations of thedatabase
Potential for need toconduct extensivefield research todetermine land usecharacteristics ateach sample worksite.
Cannot be used todetermine land useand urban designcharacteristics'impact on a specificmode choice
"The Effects of LandUse and TravelDemand ManagementStrategies onCommuting Behavior: Final Report." Prepared by CambridgeSystematics, Inc. andDeakin, Harvey,Skabardonis, Inc. forthe U.S. Department ofTransportation,November 1994.
Develops anintegrateddatabase of landusecharacteristicsand traveldemandmanagement(TDM) strategies(for a sample ofemploymentlocations) todetermine thecombined impactsof TDM programs,land use, andurban design onemployee travelbehavior.
Added land use and siteinformation from fieldobservation to the"Regulation XV" datasetof the South Coast AirQuality ManagementDistrict (which includedaggregate employeetravel characteristics andemployer incentiveprograms)
Study conducted inLos Angeles County,and thus may be lessapplicable in moredense urban areaswith factors such ashigher average densityand transit service.
Did not addressresidential trip end ofcommute, middaytravel, or trip chainingas factors whichinfluence mode choice
To simplify acomplicated datacollection process,somewhat arbitraryindicators were usedfor assessment of asite's urban designand land usecharacteristics.
Land use and urbandesign of worksite
TDM incentivestrategies
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CompressedWork Week/Flex Time(cont.)
Empiricalanalysis of theimpacts ofpersonalpreference andworkplaceconditions onmode choice
Somewhatapplicable tomultiple regions(but likely to beinfluenced heavilyby local factors ofthe study area)
Can be replicated(at moderate tohigh cost)
Does not requireextensivecomputer model
Uses actualsurvey data
Requires large datacollection process togenerate statisticallysignificant results
Personal preferenceand workplaceconditions difficult toimpact throughpublic policy
"The Influence ofEmployer RidesharingPrograms on EmployeeMode Choice." Ferguson, Erik. Transportation, vol 17,1990.
Analyzesaggregate-leveldata compiled bya large SouthernCalifornia regionalridesharingagency; assessesimpact ofemployercharacteristics onemployee modesplit
Analyzes a large data setcomprising almost 10%of Los Angeles areaworkforce
Utilizing existing agencydatabase is a cost-effective approach
Less accurate thandisaggregated (employeeby employee) data
Includes cost-effectiveness estimations
Some findings mayhave beencontradicted by morerecent studies (e.g.,study finds that largecorporations havebetter success withrideshare programs)
Aging data source: 1985 survey data
Los Angeles areafactors may beuncharacteristic ofother regions, soresults may not beapplicable elsewhere
Employer-derived datawas acquired usingdifferent methods
No estimates ofemissions impacts
Level of employereffort to encourageridesharing
Size of firm
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Analysis ofexistingprogram(s)using traveldiaries
Analyzes actualCWW/flex timeprograms
Addresses travelbehavior patterns
Can differentiatebetween work andnonwork travel,and betweenweekday andweekend travel
Potential high costassociated withimplementing traveldiaries
Does not addresstotal demand forCWW/flex time
Applicability ofresults to otherregions andconditions isuncertain
"Impacts ofCompressed WorkWeek on Vehicle Tripsand Miles Traveled: Final Report." Schoolof Urban and RegionalPlanning, University ofSouthern California, forthe California AirResources Board,October 1994. Contract No. A132-136.
Evaluates theeffectiveness ofCWW schedules;quantifies VT,VMT.
Controls for individualand householdcharacteristics to isolateindependent effect ofwork schedules on VTand VMT
Differentiated between"4/40" and "9/80" CWWschedules
Sample size (andtherefore cost) can bevaried based on level ofstatistical accuracydesired
Does not directlycalculate emissionsimpacts
Large sample size isneeded to providestatistically robustresults
Travel diaries rely onhonest recordkeepingby study respondents
Type of CWWschedule
Individual andhouseholdcharacteristics
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CompressedWork Week/Flex Time(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
Not described dac
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasuress
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation of TCMs
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specific TCMindividually; programsof multiple TCMs areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
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CompressedWork Week/Flex Time(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects (cont.)
"Transportation-RelatedImpacts of CompressedWork Week: TheDenver Experiment." Atherton, Terry J., et al. In TransportationResearch Record 845,1982.
Provides beforeand aftercomparison oftravel behavior foran experimentalcompressed-workweek program forfederalemployees inDenver
Before-and-afterapproach (with a controlgroup) accuratelyassesses changes intravel
Utilizes actual traveldiaries and surveys totrack travel patterns
Identifies some non-worktravel impacts ofcompressed work weeks
Information was completeand accurate due togovernment workplacefocus
Results not asapplicable to privateorganizations, whichmay not respond aswell to requirements toimplementcompressed workweek plans
9/80 schedule vs.4/40 schedule
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"Effects of VariableWork Hour Programson Ridesharing andOrganizationalEffectiveness: A CaseStudy, VenturaCounty." Freas, AlyssaM. and Stuart M.Anderson. CommuterTransportationServices, Inc. InTransportationResearch Record 1321,1991.
Assesses severalimpacts of a pilotemployer-basedvoluntarycompressed workweek program inVentura County
Case study was carefullydesigned to achieveeasily obtainable, usefulinformation at the end ofthe study
Studied the impact ofCWW on not onlycommutes, but alsoemployee performance,office performance, andsupervisor perspectives
Study was performedwithin a proactivecounty agency, ratherthan a privatecompany, which mayaffect the results
Does not assess VMTor emissionsreductions, onlyassesses ride sharepercent
Flextime, 4/40 weeksand 9/80 weeks
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CompressedWork Week/Flex Time(cont.)
Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"TCM Analyst 1.0 andUser's Guide." Crawford, Jason A., etal. TexasTransportation Institute. For the FederalHighwayAdministration,November 1994.
Describes acomputerizedsketch planningtool, TCM Analyst1.0, includinginput datarequirements,methods of use,and an overviewof the model'sstructure andcalculationprocedures
Provides a useful andrelatively easy instructionmanual for using TCMAnalyst 1.0
Uses MOBILE5a outputdata (emission factors)as inputs to the model,providing more accurateemission benefitcalculations for eachTCM
Program only modelslimited TCMs andcannot model multipleTCM packages
Requires several runswith MOBILE5a toobtain input emissionfactors
Modeling on regional(rather thanmicroscale) basis only
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CompressedWork Week/Flex Time(cont.)
Sketchplanning (cont.)
"Simple Methodologiesfor Quantifying VT andVMT Reductions fromTransportation Controland GrowthManagement Measuresfor Developing LocalTrip ReductionOrdinances." Evans,V. and D. Morrow. Sonoma Technology,Inc. Air & WasteManagement Assoc. 1993
Describesdevelopment ofsimplemethodologies forquantifyingreductions invehicle trips (VT)and vehicle milestraveled (VMT)from TCMs, foruse in a planning-level context; developedoriginally for theSouth Coast AirBasin
Methods to quantify VTand VMT reductions fromTCMs were based uponrelatively simple methodsfor estimating emissionsand individual TCMeffectiveness developedprior to this report for theSouth Coast AQMD
Performance-basedapproach was developedrather than usemandated transportationperformance standards
Actual experience dataused as much aspossible: estimated tripreduction levels fromeach TCM was collectedfrom other studies, andplanning-level analysisuses site-specific datainputs, thus offeringincreased precision inemissions estimates
Ranges in VT reductionsestimates address theinteractive impacts of theapplication of multipleTCMs
Equivalency factor usedto convert VMT to VT canaccount for region-specific average triplengths
Expected reductions inVT and VMT fromTCMs were estimatedbased upon a generalsurvey, so for aparticular locationdifferent assumptionsmay be needed
Applicability to otherregions outsideCalifornia limited byreport's use oftransportation dataand emissions factorsin the analysis whichwere quantified usingBURDEN and EMFACruns for 1994
Does not incorporateany consideration ofcost-effectiveness
Employeeparticipation(percentage andfrequency)
Employer-implementedalternative workweek schedule
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CompressedWork Week/Flex Time(cont.)
Sketchplanning (cont.)
"Critical Analysis ofSketch-Planning Toolsfor Evaluating theEmission Benefits ofTransportation ControlMeasures." Crawford,Jason A., andRaymond A. Krammes. Prepared by TexasTransportation Institutefor FHWA, FHWA/TX-92/1279-5. December1993.
Critical analysisand sensitivityanalysis (usingdata for El Paso,Texas) of SanDiego Associationof Governments(SANDAG) TCMTools method andthe SystemsApplicationsInternational (SAI)method;summarized inTRR 1472
Provides a thoroughreview of the state of thepractice (as of 1993)
Identifies weaknesses inthe SANDAG and SAImethods as well asstrengths
Provides detailed sketch-planning analysis for ElPaso, Texas
Many of the inputs tothe SANDAG and SAImodels are difficult toquantify
The SANDAG and SAImodels do not fullyaccount for indirectimpacts and latenttravel demand
Vehicle trips
VMT
Average vehiclespeed
Emissions (HC, CO,NOx)
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CompressedWork Week/Flex Time(cont.)
Employer TDMcost-effectivenessmodel
Estimatesreduction in andcosts of daily tripsand peak periodtrips
Aids employerdetermination ofcost-effectivenessof TDM measuresfor their particularworksite
Results may varywidely from oneemployer to the next
Many inputs may bedifficult foremployers orplanners to quantify
"TransportationDemand ManagementCost-EffectivenessModel for SuburbanEmployers." Dagang,Deborah A. JHK &Associates. InTransportationResearch Record 1404.
Reports on thedevelopment of amodel toindividuallyevaluate the cost-effectiveness of15 differentemployer-basedTDM measures insuburban settings
Focus on suburbanemployers reflectsdifferent travel-relatedcharacteristics ofsuburban and urbanareas
Spreadsheet-basedmodel is user-friendlyand readily accessible foruse at the site-specificlevel; model makessensitivity analysisrelatively simple
Eight transportationenvironments weredefined to representvarious combinations oftransportation servicecharacteristics
For employers withoutaccess to entire range ofdata necessary tooperate model, defaultvalues are included
Most employerssurveyed to developmodel were unable toprovide detailed costinformation on theTDM measures theyhad implemented
Does not calculateemissions directly
Potential for regionalbias, as model wasdeveloped in partbased on a survey ofsuburban SanFrancisco Bay Areaemployers; model alsoused the SCAQMDRegulation XV andPima Association ofGovernments TravelReduction Programemployer plandatabases
Only some TDMsincluded in modelprovide for estimatesof VT reductions
Use of default valuescould diminishesaccuracy of estimatesfor some users
Suburban employer-based TDMmeasures
Daily trips and peakperiod trips
Costs and cost-effectiveness
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CompressedWork Week/Flex Time(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from theTCM implementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing variousTCM measures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specific TCMevaluation method
Estimates VT, VMT, &emission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relativeeffectiveness ofvarioustransportationmeasure programs
Implementationmechanisms
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CompressedWork Week/Flex Time(cont.)
Comparisonand analysis ofother studies(cont.)
"The Equity and CostEffectiveness ofEmployee CommuteOptions Programs." Farkas, Z. Andrew. Morgan StateUniversity. TRB960078, January 1996.
Analyzes theresults of surveysand transportationmeasuremodeling studiesperformed for theBaltimore andPhiladelphiaregions
Shows different methodsof using the same model: Travel DemandEvaluation Modeldeveloped by COMSIS
Provides a discussion ofsocial equityconsiderations based ona survey of the tworegions
Philadelphia modelingassumed averagevehicle ridershiptargets were reachedand results are onlyapplicable relative toeach scenario
Baltimore modeling didnot estimate emissionsreductions
Rideshare promotionlevel
Parking charge level
Transit subsidylevels
Work scheduleflexibility
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CongestionPricing
Integratedtravel demand,mode choice,trafficsimulation, andemissionsmodel
If developed, anintegrated modelto simulatedemand, modechoice, trafficsimulation, andemissions couldavoid some of theshortcomingsinherent inapplying traveland emissionsmodelssequentially
Integrated model hasnot yet beendeveloped and wouldbe costly to develop
"Framework forEvaluatingTransportation ControlMeasures: Mobility, AirQuality, and EnergyTradeoffs." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch, Jul 94.SWUTC-94-60034-1
Proposes that anintegrated modelshould bedeveloped, butthe performedanalysis usescurrent modelssequentially
Provides a framework forthe development of afuture integratedtransportation andemissions model
Performed analysisnot transferable toother situations
Vehicle operatingcost levels
Vehicle occupancyrates
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Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Transportation PricingStrategies forCalifornia: AnAssessment ofCongestion, Emissions,Energy and EquityImpacts." California AirResources Board, June1995. Report No. 92-316.
Develops anduses acomprehensivetravel demandmodel to estimatethe impacts ofmultipletransportationmeasures
Uses actual, availableprice elasticities
Establishes base case bycomparing to actualtravel data
Explores interrelationsbetween pricingstrategies
Does not modelspecific travelcorridors (requiresadditional model forthis purpose)
Relies on uncertainforecasts of traveldemand
Price level, periodand location ofapplication
Price elasticity
Interrelationshipsbetween pricingstrategies
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CongestionPricing(cont.)
Travel demand/mode choicemodel (cont.)
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Travel and trafficimpact
Cost-effectiveness
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"The Effectiveness ofTransportation ControlMeasures in ReducingCongestion andImproving Air Quality." Loudon, William R., etal. JHK & Associates. Air & WasteManagementAssociation AnnualMeeting & Exhibition1993. AWMA 93-RP-149.05.
Describes adevelopedtransportationdemand modelthat integratesemissionscalculations;provides examplecalculations fromthe model
Model has a user manualthat leads the analyststep-by-step through theinput of data for regionspecific analyses
Contains extensive cost-effectiveness module
Can be used at eitherregional or a smaller areaor location
Includes exhaust andevaporative emissions
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient
Participation level dac
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel to modelVT, VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuse standardizedmethods, but take intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
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CongestionPricing(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation Pricingand Travel Behavior." Harvey, Greig W. InCurbing Gridlock: Peak-Period Fees toRelieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Overview paperon the effects oftransportationsystem pricing onactivity patternsand travelbehavior; someemissions results
Paper presents modelingresults from the SanFrancisco Bay AreaPricing Study using theSTEP model
Quantifies VMT, trips,fuel usage, ROG, CO,NOx, and CO2
Shows quantified traveland emissions modelingresults that correspond tospecific, clearly definedpricing proposals
Use of modeldeveloped for SanFrancisco Bay Areamay limit usefulness ofresults to other regions
Study acknowledgesthat the STEP modeldoes not accuratelyaccount for regionalgrowth or employmentallocation, and treatstime of day in asimplified way
VMT
Vehicle trips
Fuel usage
Emissions (ROG,CO, NOx, CO2)
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Travel costmodel
Most accurateway of measuringtrue travel costs apriori
Allowscomparison ofmultiple scenarios
Results do notnecessarily apply toother regions
Requires extensiveinformation gathering
"Impacts of CongestionPricing on Transit andCarpool Demand andSupply." Kain, John. Harvard University,1994. TRB 940444.
Uses economictheory of traveldemand, supply,and pricing, aswell as assumptionsabout the value oftime to estimatetotal travel coststo commuters
Compares impact ofcongestion pricing onvarious income groups
Provides excellentdiscussion of total costsof travel and relationshipbetween congestionpricing and transit use
Requires manyassumptions thatcould significantlyaffect results, includingrelationship betweenprice level and trafficflow speed
Does not quantifyemission reductions
Congestion pricelevel
Flow speed
Parking price level
Transit service level
Personal value oftime
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CongestionPricing(cont.)
Demandelasticity model
Simple modelbased oneconomicsfundamentals,using readilyavailable data,that capturesprimarydeterminants oftravel behavior
Can vary inputs tomodel based onlevel of complexitydesired
Model may fail toaccount for non-pricedeterminants oftravel behavior, orother congestionpricing programdesign details
"Demand ElasticityUnder Time-VaryingPrices: Case Study ofDay-of-Week VaryingTolls on Golden GateBridge." Gifford,Jonathan L. and ScottW. Talkington. GeorgeMason University,1996.
Provides a surveyoverview ofliterature on roadpricing; developsa demandelasticity model toanalyze traveldemand undertime-varyingpricing using datafrom the GoldenGate Bridge in1979-1984
Presents correlationbetween time-varyingpricing and trafficpatterns; indirectlyillustrates change in VT
Data used are fromactual applied day-of-week varying pricing
Focus on aggregatetravel behaviorprecludes analysisabout the details oftravel preferences
Results have limitedapplication to otherregions, as localvariables such aslimited transitalternatives may haveinfluenced modelresults
Use of single casestudy over period ofone price changelimits resultsapplicability in othersituations
Elasticity estimates donot include costs oftravel other than tolland gas, and includeno assessment ofpossible mode shifts
Does not quantifyemissions
Travel demandcharacteristics
Level of toll
Gasoline price
Price elasticity oftraffic
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CongestionPricing(cont.)
Statisticalanalysis ofaverage speedof congestionpricingscenarios
Existingknowledge ofspeed/emissionsrelationships canbe used toestimate theemissions impactof "peak-spreading"resulting fromcongestion pricing
Actual travel dataand congestionpricing scenarioscan be compared
Speed/emissionsrelationships underreal-world conditionsare difficult tocharacterizeaccurately and aresomewhat poorlyunderstood
Modal effects are notdirectly addressed in"average speed"analysis
May only address"peak-spreading"emissions impact,not the trip-reductionand mode shiftimpacts ofcongestion pricing
"Congestion Pricingand Motor VehicleEmissions: An InitialReview." Guensler,Randall and DanielSperling. In CurbingGridlock: Peak-PeriodFees to Relieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Examines the airquality impactslikely to resultfrom congestionpricing; focuseson the effects ofpostulatedchanges inaverage vehicleoperating speedson emission ratesby looking at fourcongestion pricingscenarios
Utilizes data fromexisting study onchanges in travelbehavior as input toanalysis
Statistical analysis isfairly simple and could bereplicated for any datasets from travel demandand emission rate models
Incorporates uncertaintyassociated with the useof speed correctionfactors
"Bootstrap" statisticalapproach toextrapolate dataresulted in highlysample-dependentnumbers, thus testsamples may not havebeen representative ofthe fleet
Impact of flowsmoothing not wellrepresented in anaverage speedmodeling regime thatis based on a limitednumber and variety oftest cycles
Changes in averagevehicle speed yieldsignificantly differentpercentage changes inemission rates forolder and newervehicles, thus fleetcomposition must beconsidered incongestion pricingscenarios
Study did not includesensitivity analysis ofthe models--howsensitive models areto errors in estimationof the independentvariable (averagespeed)
Average speedchanges andassociated emissionrate changes
Congestion pricingscenarios: targetedfreeway pricing,partial freewaypricing,comprehensivefreeway pricing,comprehensivepricing
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CongestionPricing(cont.)
Use ofeconomictheory toestimatecongestionprice levels
Based upon soundeconomic theory
Relatively easyand inexpensiveto perform
Somewhatapplicable tomultiple regions
Real life conditionsmay not be easilyaccounted for bytheory
"Freeway CongestionPricing: Another Look." Levinson, Herbert. TransportationResearch Board Paper940977, January 1994.
Identifies theappropriate levelof congestioncharges basedupon the marginalcost of driving
Analysis based uponeconomic theory andHighway CapacityManual speed-flow data
Does not addresspolitical acceptabilityor tolling optionsavailable forcongestion pricing
Prices resulting fromthe study may need tobe adjusted downwardto minimize theadverse impacts ontraveling
Does not quantifyemissions
Variation in speed-flow relationships
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Evaluativematrix
Matrix ofevaluative criteriawhich details andcomparescongestion pricingoptions could beapplied to otherregions
Relatively flexiblein level ofcomplexity andnumber ofevaluation criteriaor pricingscenarios inputinto matrix
Theoretical analysisbased on models,not actualcongestion pricingproject data
Relatively extensivelocation-specificstudy conductedfrom which matrixnumbers weredeveloped
"Evaluation ofCongestion PricingAlternatives in the TwinCities." Lari, Adeel Z.and Kenneth R.Buckeye. MinnesotaDepartment ofTransportation, January1997.
Study evaluatedthe relativerelationships andimpacts of elevencongestion pricingoptions in theTwin Citiesmetropolitan areafor 1995-96 usingstatisticallymodeled data,public outreachdata, and overallfeasibility studies
Compared elevendifferent congestionpricing scenarios for theTwin Cities area againstone another according tosame criteria
Air quality impactsmeasured in percentreductions inhydrocarbons (PM peakperiod only)
Unclear from this briefevaluative report howmatrix numbers werequantified
Matrix developedspecifically from acongestion pricingstudy for the TwinCities metropolitanarea, and thus resultsand recommendationsmay only be applicableto Minneapolis/St.Paul area
Congestion relief
Mode shift potential
Local street impacts
Air qualityimprovements
Social andgeographical equity
Land use/economicimpacts
Public acceptability
Technical feasibility
Revenue and costs
Operationaleffectiveness
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CongestionPricing(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from theTCM implementation
"Bay Bridge CongestionPricing Project: Lessons Learned toDate." Frick, Karen, etal. MetropolitanTransportationCommission, 1996. TransportationResearch Board paper961317.
Reviews andassesses theprocess by whichthe Bay AreaCongestionPricing TaskForce examinedthe viability ofvariable tolls onthe San FranciscoBay Bridge
Develops detailed,valuable lessons learnedduring theimplementation of thisspecific congestionpricing TCM
Makes recommendationson how to develop acongestion pricing TCMthat gains the approval ofthe public and publicofficials
Does not evaluate theend resulteffectiveness: VT,VMT, emissionsreduced
Public reaction to themeasure undervarying toll levelsand alternativecommute options
Allocation of tollmonies and equityissues
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"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing variousTCM measures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specific TCMevaluation method
Estimates VT, VMT, &emission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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CongestionPricing(cont.)
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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"Demand ElasticityUnder Time-VaryingPrices: Case Study ofDay-of-Week VaryingTolls on Golden GateBridge." Gifford,Jonathan L. and ScottW. Talkington. GeorgeMason University,1996.
Provides a surveyoverview ofliterature on roadpricing; developsa demandelasticity model toanalyze traveldemand undertime-varyingpricing using datafrom the GoldenGate Bridge in1979-1984
Survey includes boththeoretical and appliedwork
Focus on aggregatetravel behaviorprecludes analysisabout the details oftravel preferences
Results limited inindirect applicability tocongestion pricing onbridges
Travel demandcharacteristics
Level of toll
Gasoline price
Price elasticity oftraffic
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"ManagingTransportationDemand: MarketsVersus Mandates." Giuliano, Genevieve,and Martin Wachs. Reason Foundation,September 1992. Policy Insight No. 142.
Comparescongestion pricingwith RegulationXV for theSouthernCalifornia area;describes prosand cons of eachmeasure anddiscussesimplications
Provides typology ofTCMs and identifieseffectiveness andcommon barriers toimplementation
Simple side-by-sidecomparison of VMTreduction and cost-effectiveness for eachTCM
Makes policyrecommendations toimprove each TCM
Provides little detailabout logistics ofimplementing thepolicyrecommendations
Does not quantifyemission reductions
Direct vs. indirectimplementation
Market-based vs.performance-basedimplementation
Efficiency and equityconsiderations
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CongestionPricing(cont.)
Comparisonand analysis ofother studies(cont.)
"Transportation Pricingand Travel Behavior." Harvey, Greig W. InCurbing Gridlock: Peak-Period Fees toRelieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Overview paperon the effects oftransportationsystem pricing onactivity patternsand travelbehavior; someemissions results
Paper reviews empiricalresults and anecdotalfrom severaltransportation pricingprojects and studies
Review of existing resultsfocuses on aggregatedemand elasticity
Wide variability ofresults reviewed limitstheir usefulness
Aggregate demandelasticity
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Database/Information
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specifictransportationmeasure individually;programs of multipletransportationmeasures areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
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Database/Information(cont.)
Samplesurveys ofridematchingdatabaseprogramsuccess
Uses statisticallyrepresentativesample populationto make estimatesof overall impactof ridematchingservices onridesharing
Sample size (andtherefore cost)can be variedbased on level ofstatisticalaccuracy desired
Surveys can bedone periodicallyto determinechanges inrideshareplacement ratesover time, andimpacts of specialpromotions suchas "Try Transit"weeks
Surveys can entailsignificant costs
"Revolving door"characteristic ofridesharing programscan be difficult toaddress withaccuracy
Relationshipbetween ridesharingparticipation, VMT,and emissionsrequires additionalanalysis
If surveys areperformed differentlyin different regions,direct comparisonsof results may not bevalid
"Rideshare PlacementMeasurement: AProposed StandardMethodology." King,Michael, and BarbaraAlderson. CaliforniaState University atChico, June 1995.
Developsmethodology forquantifyingrideshareplacement levelsfor ridematchingservices;discusses pilottesting ofmethodology(note: thismethodology iscurrently used byRIDES for BayArea Commutersin the SanFrancisco BayArea).
Survey methodology isgeneric and can beapplied to any region
Methodologydistinguishes betweenthree types of rideshareplacements (trial,maintenance, andongoing) to reflect theirdifferent impact on traveland emissions
Only quantifiesrideshare placement;does not directlyquantify VMT andemissions impact
Rideshare placementrate (trial,maintenance, andongoing)
Survey responserate
Statistical samplingerror
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EmissionsFees
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Transportation PricingStrategies forCalifornia: AnAssessment ofCongestion, Emissions,Energy and EquityImpacts." California AirResources Board, June1995. Report No. 92-316.
Develops anduses acomprehensivetravel demandmodel to estimatethe impacts ofmultipletransportationmeasures
Establishes base case bycomparing to actualtravel data
Explores interrelationsbetween pricingstrategies
Does not contain ahighway-networkmodel to include level-of-service changes
Forecasts rely onestimations ofchanges in householdtravel data
Fee level as afunction of mileage,make, model &model year
Price elasticity
Interrelationshipsbetween pricingstrategies
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EmissionsFees (cont.)
Travel demand/mode choicemodel (cont.)
"Transportation Pricingand Travel Behavior." Harvey, Greig W. InCurbing Gridlock: Peak-Period Fees toRelieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Overview paperon the effects oftransportationsystem pricing onactivity patternsand travelbehavior; someemissions results
Paper presents modelingresults from the SanFrancisco Bay AreaPricing Study using theSTEP model
Quantifies VMT, trips,fuel usage, ROG, CO,NOx, and CO2
Shows quantified traveland emissions modelingresults that correspond tospecific, clearly definedpricing proposals
Use of modeldeveloped for SanFrancisco Bay Areamay limit usefulness ofresults to other regions
Study acknowledgesthat the STEP modeldoes not accuratelyaccount for regionalgrowth or employmentallocation, and treatstime of day in asimplified way
VMT
Vehicle trips
Fuel usage
Emissions (ROG,CO, NOx, CO2)
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EmployeeCommuteSubsidies
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Subsidy level
Average vehicleridership
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EmployeeCommuteSubsidies(cont.)
Travel demand/mode choicemodel (cont.)
"A Survey and Analysisof EmployeeResponses toEmployer-SponsoredTrip ReductionIncentive Programs." Schreffler, Eric N., andMortero, Jose.COMSIS Corp.California AirResources Board,February 1994. Contract No. A983-187.
Describes resultsof new surveydata regardingemployee travelbehavior; usesmode choice andtravel demandmodel to predictimpacts of certainemployer-basedtransportationmeasures
Clearly explains theprocess that was used: survey data acquisition,mode choicecomputation, and TCMeffectiveness model use
Data requirements aremore readily availablethan other models
User-friendly model isavailable for outside use;users guide is alsoavailable
Survey links incentivesdirectly to impacts ontravel behavior
Model includes anawareness sub-modelthat simulates how manypeople know about thepossible TCMs availableto them
Does not accuratelyaddress trip-chainingand VMT reductions(only trips)
Household conditionsare not extensivelyaccounted for
Cost-effectivenesswas not calculated
Employer-levelanalyses only, withfocus upon incentiveTCMs
Guaranteed ridehome
Company vanpools
Preferential parking
Parking fees forridesharers
Carpool subsidies &transportationallowances
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"Selection andEvaluation of TravelDemand ManagementMeasures." Taylor,Christopher J., et al. TRB 971114, January1997.
Uses TravelDemandEvaluation Modeldeveloped byCOMSIS toevaluate theimpact oftransportationmeasures onmode choice andVT for theSyracuse, NYmetropolitan area
Uses journey-to-workcensus data to developestimates of zone-to-zone travel
Evaluates both area-wideprograms and employer-based programs
Assesses revenuegeneration potential andtransit subsidies
Sufficiently detailedjourney-to-workcensus data may notbe available for allcities: Syracuse hasthis data available dueto a pilot program
Requires assumingsome estimates ofeffectiveness
Does not quantifyemissions reductions
Transit fare levelsand travel time
HOV lane timesavings
Parking costs
Employer transitencouragement level
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EmployeeCommuteSubsidies(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel to modelVT, VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuses standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
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EmployeeCommuteSubsidies(cont.)
Statisticalanalysis of theimpacts of landusecharacteristicsand TDMstrategies onmode choice
Use of PrincipleComponentsAnalysisgeneratedcompositevariables (groupsof land usecharacteristicswith similarimpacts)
Standard analysisof variance usingprinciplecomponentsallowedexamination of theeffects of land useand TDMincentivestrategies onmode choiceindividually and incombination.
Resultstransferable toother urban areasin terms of relativeranking ofimportance of theland use and TDMfactors analyzed.
Precise causalityand individualimpacts of factorssuch as transitavailability or urbandensity on modechoice cannot bemeasured due tolimitations of thedatabase
Potential for need toconduct extensivefield research todetermine land usecharacteristics ateach sample worksite.
Cannot be used todetermine land useand urban designcharacteristics'impact on a specificmode choice
"The Effects of LandUse and TravelDemand ManagementStrategies onCommuting Behavior:Final Report." Prepared by CambridgeSystematics, Inc. andDeakin, Harvey,Skabardonis, Inc. forthe U.S. Department ofTransportation,November 1994.
Develops anintegrateddatabase of landusecharacteristicsand traveldemandmanagement(TDM) strategies(for a sample ofemploymentlocations) todetermine thecombined impactsof TDM programs,land use, andurban design onemployee travelbehavior.
Quantified interactiveeffect of financialincentives and one ormore land use sitecharacteristics.
Added land use and siteinformation from fieldobservation to the"Regulation XV" datasetof the South Coast AirQuality ManagementDistrict (which includedaggregate employeetravel characteristics andemployer incentiveprograms)
Study conducted inLos Angeles County,and thus may be lessapplicable in moredense urban areaswith factors such ashigher average densityand transit service.
Did not addressresidential trip end ofcommute, middaytravel, or trip chainingas factors whichinfluence mode choice
To simplify acomplicated datacollection process,somewhat arbitraryindicators were usedfor assessment of asite's urban designand land usecharacteristics.
Land use and urbandesign of worksite
TDM incentivestrategies
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EmployeeCommuteSubsidies(cont.)
Empiricalanalysis of theimpacts ofpersonalpreference andworkplaceconditions onmode choice
Somewhatapplicable tomultiple regions(but likely to beinfluenced heavilyby local factors ofthe study area)
Can be replicated(at moderate tohigh cost)
Does not requireextensivecomputer model
Uses actualsurvey data
Requires large datacollection process togenerate statisticallysignificant results
Personal preferenceand workplaceconditions difficult toimpact throughpublic policy
"The Influence ofEmployer RidesharingPrograms on EmployeeMode Choice." Ferguson, Erik. Transportation, vol 17,1990.
Analyzesaggregate-leveldata compiled bya large SouthernCalifornia regionalridesharingagency; assessesimpact ofemployercharacteristics onemployee modesplit
Analyzes a large data setcomprising almost 10%of Los Angeles areaworkforce
Utilizing existing agencydatabase is a cost-effective approach
Less accurate thandisaggregated (employeeby employee) data
Includes cost-effectiveness estimations
Some findings mayhave beencontradicted by morerecent studies (e.g.,study finds that largecorporations havebetter success withrideshare programs)
Aging data source: 1985 survey data
Los Angeles areafactors may beuncharacteristic ofother regions, soresults may not beapplicable elsewhere
Employer-derived datawas acquired usingdifferent methods
No estimates ofemissions impacts
Level of employereffort to encourageridesharing
Size of firm
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Parking supplyand demandmodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires computermodel
Potentially high costto use
"Air Quality Offsets forParking." Loudon,William, et al. InTransportationResearch Record 1232,1992.
Develops anduses parkingsupply model fordowntownPortland toestimate COemissions
Uses observed price andtravel time sensitivities
Uses proven models oftravel behavior
Incorporates integratedCO emissions model
Requires parkingdatabase: number ofspaces, location, type,use patterns
Requires traveldatabase: time ofarrival, travel & workmode split
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EmployeeCommuteSubsidies(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
Not described dac
"Employee TripReduction WithoutGovernment Mandates: Cost and EffectivenessEstimates FromChicago." Pagano,Anthony and JoAnnVerdin. University ofIllinois at Chicago. TransportationResearch Board Paper971281, 1997.
Evaluated thecost andeffectiveness ofemployee tripreductionprograms throughthe use of anindependentevaluation ofdemonstrationprojectsimplemented inthe Chicago area
Estimates planning,maintenance, andvoluntary implementation,and incentive costs fortrip reduction programs
Intensive data collection,especially for costestimates, includingbefore and after surveysand interviews ofprogram administratorsparticipating in thedemonstration projects
Addresses statisticalrelationships oforganization type to costsand outcomes, of coststo strategies andincentives, of outcomesto strategies andincentives, and of cost tooutcomes
Addresses differences inoutcome byorganizational type(factory vs. office)
Made generalizedassumption of staffcosts needed toimplement tripreduction programs
Intensive datacollection requiresdemonstration projectand surveys, orapplication of Chicagoarea data
Results have limitedapplication to otherregions, as localChicago variablessuch as availability oftransit alternativesmay have influencedmodel results
Trip reductionprogramimplementationprocess utilized
Obstacles andsuccess factors
Program costs andeffectiveness
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EmployeeCommuteSubsidies(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specifictransportationmeasure individually;programs of multipletransportationmeasures areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"Evaluating theEffectiveness ofTransportation ControlMeasures for San LuisObispo County,California." Morrow,David D., San LuisObispo Air PollutionControl District, 1992.
Develops anduses a calculationmethodology forestimating the tripreduction and airquality benefits ofemployer tripreductionrequirements inSan Luis ObispoCounty
Methodologies aredeveloped specifically forthe employer tripreduction program
Explains calculationprocess in detail
Requires extensive,region-specificinformation toaccurately estimatebenefits andeffectiveness of theprogram
Assumes a level ofprogram participation(as required by themeasure)
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EmployeeCommuteSubsidies(cont.)
Employer TDMcost-effectivenessmodel
Estimatesreduction in andcosts of daily tripsand peak periodtrips
Aids employerdetermination ofcost-effectivenessof TDM measuresfor their particularworksite
Results may varywidely from oneemployer to the next
Many inputs may bedifficult foremployers orplanners to quantify
"TransportationDemand ManagementCost-EffectivenessModel for SuburbanEmployers." Dagang,Deborah A. JHK &Associates. InTransportationResearch Record 1404.
Reports on thedevelopment of amodel toindividuallyevaluate the cost-effectiveness of15 differentemployer-basedTDM measures insuburban settings
Focus on suburbanemployers reflectsdifferent travel-relatedcharacteristics ofsuburban and urbanareas
Spreadsheet-basedmodel is user-friendlyand readily accessible foruse at the site-specificlevel; model makessensitivity analysisrelatively simple
Eight transportationenvironments weredefined to representvarious combinations oftransportation servicecharacteristics
For employers withoutaccess to entire range ofdata necessary tooperate model, defaultvalues are included
Most employerssurveyed to developmodel were unable toprovide detailed costinformation on theTDM measures theyhad implemented
Does not calculateemissions directly
Potential for regionalbias, as model wasdeveloped in partbased on a survey ofsuburban SanFrancisco Bay Areaemployers; model alsoused the SCAQMDRegulation XV andPima Association ofGovernments TravelReduction Programemployer plandatabases
Only some TDMsincluded in modelprovide for estimatesof VT reductions
Use of default valuescould diminishesaccuracy of estimatesfor some users
Suburban employer-based TDMmeasures
Daily trips and peakperiod trips
Costs and cost-effectiveness
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EmployeeCommuteSubsidies(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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EmployeeCommuteSubsidies(cont.)
Comparisonand analysis ofother studies(cont.)
"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relativeeffectiveness ofvarioustransportationmeasure programs
Implementationmechanisms
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"ManagingTransportationDemand: MarketsVersus Mandates." Giuliano, Genevieve,and Martin Wachs. Reason Foundation. Policy Insight No. 142,September 1992.
Comparescongestion pricingwith RegulationXV for theSouthernCalifornia area;describes prosand cons of eachmeasure anddiscussesimplications
Provides typology oftransportation measuresand identifieseffectiveness andcommon barriers toimplementation
Simple side-by-sidecomparison of VMTreduction and cost-effectiveness for eachtransportation measure
Makes policyrecommendations toimprove eachtransportation measure
Provides little detailabout logistics ofimplementing thepolicyrecommendations
Does not quantifyemission reductions
Direct vs. indirectimplementation
Market-based vs.performance-basedimplementation
Efficiency and equityconsiderations
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"The Equity and CostEffectiveness ofEmployee CommuteOptions Programs." Farkas, Z. Andrew. Morgan StateUniversity. TRB960078, January 1996.
Analyzes theresults of surveysand transportationmeasuremodeling studiesperformed for theBaltimore andPhiladelphiaregions
Shows different methodsof using the same model: Travel DemandEvaluation Modeldeveloped by COMSIS
Provides a discussion ofsocial equityconsiderations based ona survey of the tworegions
Philadelphia modelingassumed averagevehicle ridershiptargets were reachedand results are onlyapplicable relative toeach scenario
Baltimore modeling didnot estimate emissionsreductions
Rideshare promotionlevel
Parking charge level
Transit subsidylevels
Work scheduleflexibility
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Episodic/seasonalcontrols
Sample surveyanalysis ofexistingprogram(s)
Uses samplepopulation tomake estimates ofoverall impact ofepisodic/ seaonalcontrols
Sample size (andtherefore cost)can be variedbased on level ofstatisticalaccuracy desired
Surveys can bedone periodicallyto determinechanges inprogrameffectiveness overtime
Surveys can entailsignificant costs
Daily travel patternsare influenced by somany things thatisolating the impactof episodic programscan be difficult toaddress withaccuracy throughstatistical sampling
If surveys areperformed differentlyin different regions,direct comparisonsof results may not bevalid
"Sacramento RegionalSpare the Air 1996: AReport on Two PublicOpinion Surveys." Lamare, Jude, TheCleaner AirPartnership. 1997.
Summarizesfindings regardingpublicparticipation inSacramento'sSpare the Airprogram, basedon telephoneinterviews
Generates estimates ofawareness of programand participation inprogram (in terms of tripsreduced)
By identifying reasons forprogram participation,and how participantsshifted trips, study resultscan be used to improveepisodic program design
Telephone surveyresponses may bebiased for severalreasons
Uses only brieftelephone interviews
Survey repondentsmay not be statisticallyrepresentative ofregional population
Only uses survey datafrom one smogepisode in a givenyear, with no controlgroup
Unable to assess withconfidence therelationship betweenprogramcharacteristics andprogram effectiveness
Awareness ofepisodic program
Participation inepisodic program
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Feebate Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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Fuel TaxIncreases
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Transportation PricingStrategies forCalifornia: AnAssessment ofCongestion, Emissions,Energy and EquityImpacts." California AirResources Board, June1995. Report No. 92-316.
Develops anduses acomprehensivetravel demandmodel to estimatethe impacts ofmultipletransportationmeasures
Establishes base case bycomparing to actualtravel data
Explores interrelationsbetween pricingstrategies
Does not contain ahighway-networkmodel to include level-of-service changes
Forecasts rely onestimations ofchanges in householdtravel data
Tax level
Price elasticity
Interrelationshipsbetween pricingstrategies
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Fuel TaxIncreases(cont.)
Travel demand/mode choicemodel (cont.)
"The Effectiveness ofTransportation ControlMeasures in ReducingCongestion andImproving Air Quality." Loudon, William R., etal. JHK & Associates. Air & WasteManagementAssociation AnnualMeeting & Exhibition1993. AWMA 93-RP-149.05.
Describes adevelopedtransportationdemand modelthat integratesemissionscalculations;provides examplecalculations fromthe model
Model has a user manualthat leads the analyststep-by-step through theinput of data for regionspecific analyses
Contains extensive cost-effectiveness module
Can be used at eitherregional or a smaller areaor location
Includes exhaust andevaporative emissions
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient
Tax level dac
"Transportation Pricingand Travel Behavior." Harvey, Greig W. InCurbing Gridlock: Peak-Period Fees toRelieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Overview paperon the effects oftransportationsystem pricing onactivity patternsand travelbehavior; someemissions results
Paper presents modelingresults from the SanFrancisco Bay AreaPricing Study using theSTEP model
Quantifies VMT, trips,fuel usage, ROG, CO,NOx, and CO2
Shows quantified traveland emissions modelingresults that correspond tospecific, clearly definedpricing proposals
Use of modeldeveloped for SanFrancisco Bay Areamay limit usefulness ofresults to other regions
Study acknowledgesthat the STEP modeldoes not accuratelyaccount for regionalgrowth or employmentallocation, and treatstime of day in asimplified way
VMT
Vehicle trips
Fuel usage
Emissions (ROG,CO, NOx, CO2)
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Fuel TaxIncreases(cont.)
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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"Transportation Pricingand Travel Behavior." Harvey, Greig W. InCurbing Gridlock: Peak-Period Fees toRelieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Overview paperon the effects oftransportationsystem pricing onactivity patternsand travelbehavior; someemissions results
Paper reviews empiricalresults and anecdotalfrom severaltransportation pricingprojects and studies
Review of existing resultsfocuses on aggregatedemand elasticity
Wide variability ofresults reviewed limitstheir usefulness
Aggregate demandelasticity
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General Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requirescomplicatedcomputer model
Potentially high costto use
"Travel Markets: AnApproach to TCMEffectivenessEvaluation." Torluemke, Donald A. Ekistic MobilityConsultants, 1992.
Describes a TDMevaluationmethodology andmodel (GRACIE)that utilizes"travel market"characteristicsrather than origin-destination datato classify trips
Travel marketsegmentation providesuseful groupings withsimilar consumerattributes that can beaffected homogeneouslyby TDMs
Travel markets are moreeasily understood
Travel market data islacking; requiresconverting origin-destination data totravel market data
Does not show resultsof using the model
Travel marketcharacteristics
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General(cont.)
Modalemissionsmodel
A modalemissions model,which estimatesemissions as afunction of vehicleoperating modesrather thanaverage vehiclespeeds, wouldgreatly improvethe evaluation oftransportationmeasures thataffect the modaloperation ofvehicles
An emissions model,unless integratedwith a travel model,does not calculatetravel activityimpacts oftransportationmeasures
Modal emissionsmodels are still in thedevelopment stage
"Overview of theGeorgia Tech GIS-Based ModalEmissions Model." Guensler, Randall, etal. Georgia TechResearch Partnership. April 1997.
DescribesGeorgia Tech'sdevelopment of amotor vehicleemissions modelwithin ageographicinformationsystem (GIS)framework
Model is GIS-based, andis compatible with theanalytical frameworkscurrently employed bymost state DOTs andmetropolitan planningorganizations
All model components,assumptions, andalgorithms can bevalidated against real-world data
Paper discusses how themodel would providebetter evaluations ofcertain transportationmeasures such as gross-emitter strategies
Model is still underdevelopment
Fleet composition
Vehicle activity
Emission rates
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High-OccupancyVehicleFacilities
Integratedtravel demand,mode choice,trafficsimulation, andemissionsmodel
If developed, anintegrated modelto simulatedemand, modechoice, trafficsimulation, andemissions couldavoid some of theshortcomingsinherent inapplying traveland emissionsmodelssequentially
Integrated model hasnot yet beendeveloped and wouldbe costly to develop
"Framework forEvaluatingTransportation ControlMeasures: Mobility, AirQuality, and EnergyTradeoffs." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch, Jul 94,SWUTC-94-60034-1
Proposes that anintegrated modelshould bedeveloped, butthe performedanalysis usescurrent modelssequentially
Provides a framework forthe development of afuture integratedtransportation andemissions model
Performed analysisnot transferable toother situations
Vehicle operatingcost levels
Vehicle occupancyrates
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High-OccupancyVehicleFacilities(cont.)
Integratedplanning/simulationmodel
Combines thestrengths ofregionaltransportationplanning modelsand trafficsimulation models
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires verydetailed input data
Requires complexcomputer model
Potentially high costto use
"IntelligentTransportation SystemsImpact AssessmentFramework: FinalReport." VolpeNational TransportationSystems Center,September 30, 1995
Describesdevelopment andapplication of ananalytical tool topredict ITSimpacts, with afocus onAdvanced TrafficManagementSystems
Model integratestransportation planningand traffic simulation inan iterative fashion, andincludes emissions andfuel consumptionmodules
Report describes use ofmodel to analyze thepotential use of ITS in theI-880 corridor in AlamedaCounty, California,modeling ramp metering,traffic signal coordination,integrated trafficmanagement, incidentmanagement, and HOVlanes
Emissions module usesaccepted EMFAC andMOBILE factors
Relatively high costand complexity
Locally specific inputdata makes the I-880results of limited use inother areas
OperationalMeasures ofEffectiveness: VMT,traffic volume,average vehiclespeed, vehicle hoursof delay, fuelconsumption
Emission Measuresof Effectiveness: CO, HC, NOx
Safety Measures ofEffectiveness: personal injurylevels, propertydamage, totalaccidents
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Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Vehicle occupancy:2, 3, or 4 or morepeople required forHOV lane use
Preferential parking
Average vehicleridership
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High-OccupancyVehicleFacilities(cont.)
Travel demand/mode choicemodel (cont.)
"The Effects of NewHigh-OccupancyVehicle Lanes onTravel and Emissions." Johnston, Robert A.,and Raju Ceerla. InTransportationResearch A, vol. 30 no.1, pp. 35-50, 1996.
Reviews pastmodeling effortsand traveldemandsimulations ofHOV lanes,includinginteractionsbetween HOVlanes, pricingmeasures, transitexpansion, andtransit-orienteddevelopment.
Incorporates feedbackprocedure to account forpotential induced traveldemand resulting fromnew HOV lanes
Compares HOV laneswith other transportationstrategies, includingpricing, transitimprovements, andtransit-orienteddevelopment
Uses availableEMFAC7E emissionrates to calculate TOG,NOx, and CO
Results are gearedtoward specificSacramento policyproposals, and are notdirectly transferable toother areas
EMFAC7E factors areCalifornia-specific
Travelcharacteristics: VMT, total v ehiclehours, vehicle hoursof delay, transit trips,HOV trips
Emissions: TOG,CO, NOx
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"Selection andEvaluation of TravelDemand ManagementMeasures." Taylor,Christopher J., et al. TRB 971114, January1997.
Uses TravelDemandEvaluation Modeldeveloped byCOMSIS toevaluate theimpact oftransportationmeasures onmode choice andVT for theSyracuse, NYmetropolitan area
Uses journey-to-workcensus data to developestimates of zone-to-zone travel
Evaluates both area-wideprograms and employer-based programs
Assesses revenuegeneration potential andtransit subsidies
Sufficiently detailedjourney-to-workcensus data may notbe available for allcities: Syracuse hasthis data available dueto a pilot program
Requires assumingsome estimates ofeffectiveness
Does not quantifyemissions reductions
Transit fare levelsand travel time
HOV lane timesavings
Parking costs
Employer transitencouragement level
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Vehiclequeuing model
Calculatesaggregate vehicledelay (not justindividual vehicletravel time)
Applicable to anyhighway
Analyst can varyinput parameters
Relatively low costto use
Requires computermodel
Theoretical ratherthan empirical
Requires manysimplifyingassumptions
"An Analysis of theEffectiveness of HighOccupancy VehicleLanes." Dahlgren, J.W. Institute ofTransportation Studies,UC Berkeley, 1994. UCB-ITS-DS-94-2.
Develops anduses extensivefreeway queuingmodel thatsimulates theaddition of HOVor generalpurpose lanes
Uses range of travelmode (HOV or LOV)sensitivities
Addresses impact onroute choice, travel time,induced trips & growth
Incorporates integratedemissions model
Requires limited data
Assumes bottleneckcreates delay (notmaximum flowcapacity)
Percentage of HOVdrivers
Initial vehicle delay
Number of lanes
Travel timeelasticities
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High-OccupancyVehicleFacilities(cont.)
Freewaythroughputmodel
May be applicableto actual corridors,given accurateknowledge of keyassumptions
Low to moderatecost
Assumptions arerequired that mayheavily impact theresults
"Negative Impacts ofHOV Facilities onTransit." Vuchic,Vukan R., et al.University ofPennsylvania/University of Delaware. January1995. TRB 950543.
Surveyed thequantity andquality of bus andHOV lanes inseveral cities;modeleddifferences inimpacts betweenbus-only andHOV lanes
Provides quantitative andqualitative arguments forbus-only lanes
Results are consistentwith actual demonstrationproject findings, andshow potential to reduceVMT
Amount andcomposition of latentdemand for freewayuse is assumed
Shifts in passengersfrom SOV to HOVlanes are assumed
Does not modelemissions
Addition of bus-onlyor HOV lane
Conversion of bus-only or HOV lane
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Emissiondispersionmodel (used forfreeways)
Readily availablemodels
Applicable to anyhighway
Analyst can varyinput parameters
Relatively low costto use
Requires computermodel
Requires manysimplifyingassumptions
"Air Quality Impacts ofHOV Facilities." Chatterjee, Aun. et al. University ofTennessee, January1996. TRB 960425.
Uses anemissionsdispersion modelto estimate COand NOxconcentrationsalong a freewaywith HOV lanes
Establishes and upperand lower bound onemission concentrationimpacts due to HOVlanes
Includes impacts of latentdemand
Highly theoreticalstudy with idealizedconditions; does notuse actual data
Assumes mode choicesplits
Bus-only lanes vs.multiple passengerlanes
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Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"Evaluating the SeattleI-5 North HOV Lane 2+OccupancyRequirementDemonstration." Turnbull, Katherine F.et al. TexasTransportation Institute. January 1993.
Summarizes theimpact (on theHOV lane andgeneral purposelanes) of ademonstrationproject whichlowered theminimum vehicleoccupancyrequirement onthe I-5 North HOVlanes in Seattlefrom 3 or morepersons pervehicle to 2 ormore persons pervehicle
Provides overview ofgeneral trends andimpacts of a reduction inHOV lane requirements
Information evaluated instudy was obtainedthrough special surveysand from ongoingmonitoring efforts byWashington State'sDepartment ofTransportation
Factors under study intravel corridor mayhave been influencedand confounded byadditional variables
Changes in travelcharacteristics as aresult of demonstrationproject may not haveemerged immediatelyafter implementation,and thus may notshow up in evaluation
Analysis limited byavailability of data,especially for theperiod immediatelypreceding the start ofthe demonstration
Impact of changingHOV lane vehicleoccupancyrequirements
Traffic levels andtraffic conditionsduring morning andafternoon peak hoursand peak periods
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High-OccupancyVehicleFacilities(cont.)
Case studyanalysis
Analyzing casestudies isrelatively easy andinexpensive
Different casestudies can becompared todetermine factorsinfluencing theeffectiveness ofan HOV strategy
Case-study analysisfrequently does notprovide rigorousquantitative results
Effectiveness ofcase studies may bedue to local factorsspecific to that case
"High-OccupancyVehicle Project CaseStudies: HistoricalTrends and ProjectExperiences." Turnbull,Katherine. TexasTransportation Institute. Prepared for FederalTransit Administration,August 1992.
Presents theexamination ofhistorical trendsand currentexperiences withHOV projects onfreeways or inseparate rights-of-way in selectedcase studiesnationwide; looksspecifically at airquality andemissions effectsin a Houston casestudy
Selected case studiesevaluated represent amix of old and newprojects, HOV designtreatments, andgeographic coverage
Provides a summary ofthe experience to datewith a variety of HOVprojects in NorthAmerica.
Utilizes existing datafrom case studies, suchas mode choice surveysof HOV facility users todraw general conclusions
Identifies measures ofeffectiveness for use inevaluating each of thefactors analyzed, andprovides examples ofhow the case studiesrelate to the differentmeasures
Conclusions andcomparisons drawnfrom relatively littledata in some cases
Effectiveness of HOVfacilities not calculatedin terms of emissionsbut are generally givenin before-and-afterperson and vehiclevolume comparisonsand percentagesrelative to generaltraffic lanes
Compares casestudies of ongoingprojects of differingages, and in differentlocations (each withunique factors such asweather, transitissues, and publicopinions); thus,conclusions drawncould include errors inconsistency orcomparability of data
Does not provideemissions estimates
Person movementcapacity and per-lane efficiency of thefreeway facility
Bus serviceoperating efficiencies
Travel time savingsand trip timereliability
Air quality andenergy impacts
Impacts on theoperation of thefreeway general-purpose lanes
Safety
Public support
Cost-effectiveness
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High-OccupancyVehicleFacilities(cont.)
Case studyanalysis (cont.)
"Assessment of High-Occupancy VehicleFacilities in NorthAmerica: ExecutiveReport." Turnbull,Katherine. TexasTransportation Institute. Prepared for FederalTransit Administration,August 1992.
Included in aseries of reportsprepared as partof a three-yearassessment
Selected case studiesevaluated represent amix of old and newprojects, HOV designtreatments, andgeographic coverage
Provides a summary ofthe experience to datewith a variety of HOVprojects in NorthAmerica.
Utilizes existing datafrom case studies, suchas mode choice surveysof HOV facility users todraw general conclusions
Identifies measures ofeffectiveness for use inevaluating each of thefactors analyzed, andprovides examples ofhow the case studiesrelate to the differentmeasures
Conclusions andcomparisons drawnfrom relatively littledata in some cases
Effectiveness of HOVfacilities not calculatedin terms of emissionsbut are generally givenin before-and-afterperson and vehiclevolume comparisonsand percentagesrelative to generaltraffic lanes
Compares casestudies of ongoingprojects of differingages, and in differentlocations (each withunique factors such asweather, transitissues, and publicopinions); thus,conclusions drawncould include errors inconsistency orcomparability of data
Does not provideemissions estimates
Person movementcapacity and per-lane efficiency of thefreeway facility
Bus serviceoperating efficiencies
Travel time savingsand trip timereliability
Air quality andenergy impacts
Impacts on theoperation of thefreeway general-purpose lanes
Safety
Public support
Cost-effectiveness
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"TCM Analyst 1.0 andUser's Guide." Crawford, Jason A., etal. TexasTransportation Institute. For the FederalHighwayAdministration,November 1994.
Describes acomputerizedsketch planningtool, TCM Analyst1.0, includinginput datarequirements,methods of use,and an overviewof the model'sstructure andcalculationprocedures
Provides a useful andrelatively easy instructionmanual for using TCMAnalyst 1.0
Uses MOBILE5a outputdata (emission factors)as inputs to the model,providing more accurateemission benefitcalculations for eachTCM
Program only modelslimited TCMs andcannot model multipleTCM packages
Requires several runswith MOBILE5a toobtain input emissionfactors
Modeling on regional(rather thanmicroscale) basis only
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High-OccupancyVehicleFacilities(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (localinputs may play asignificant role indetermining thetravel and emissionsimpacts of HOVfacilities)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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"The Effects of NewHigh-OccupancyVehicle Lanes onTravel and Emissions." Johnston, Robert A.,and Raju Ceerla. InTransportationResearch A, vol. 30 no.1, pp. 35-50, 1996.
Reviews pastmodeling effortsand traveldemandsimulations ofHOV lanes
Provides an overviewand critique of previousHOV impact assessmentefforts, withrecommendations forimprovements
Summarizes modelingissues related to theFederal and CaliforniaClean Air Acts
Various travelcharacteristics,depending on thespecific studyreviewed
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High-OccupancyVehicleFacilities(cont.)
Comparisonand analysis ofother studies(cont.)
"Assessment of High-Occupancy VehicleFacilities in NorthAmerica: ExecutiveReport." Turnbull,Katherine. TexasTransportation Institute. Prepared for FederalTransit Administration,August 1992.
Summarizes anassessment ofHOV laneprojects onfreeways orseparate rights-of-way in NorthAmerica; includessuggestedprocedures forevaluating HOVprojects(summarizes fourother reportsprepared as partof the samethree-yearassessment)
Identifies clear objectivesfor developing HOVfacilities andcorresponding measuresof effectiveness, as wellas general thresholdguidelines (ranges) anddata needs
Details suggestedapproach for evaluatingoperating HOV projects
Focuses on overallimpacts of HOV facilitieson person and vehiclemovement, costeffectiveness,implementation risks andflexibility, and use
Extensive data collectiondone which provides alarge data set detailingthe status of HOVfacilities in North America(including HOV utilizationby passengers andvehicles)
Compares casestudies of ongoingprojects of differingages, and in differentlocations (each withunique factors such asweather, transitissues, and publicopinions); thus,conclusions drawncould include errors inconsistency orcomparability of data
Conclusions andcomparisons drawnfrom relatively littledata in some cases
Does not provideemissions estimates
Design treatments,operating scenarios,enforcementtechniques,utilization levels, andgeneral experienceswith HOV facilities
Institutionalarrangementsassociated with thedevelopment andoperation, historicaltrends in use, andimpacts of thefacilities
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"HOV Lanes and RampMetering: Can TheyWork Together for AirQuality?" Shoemaker,Bill R. and Edward C.Sullivan. TransportationResearch Board Paper940444. January 1994.
Comments on theanalysis processused to assessthe air qualityimpacts of HOVland and rampmetering projects,and examines thedegree to whichthese measuresare effective andcompatible wherejointly applied toimprove freewayoperations
Illustrates the process ofanalysis and decision-making, as well as thekey role of analyticalmodeling, required in theSan Francisco Bay Areato gain approval for HOVlane and ramp meteringprojects at the regionallevel
Examines theinterrelationships, andpotentially perverseeffects, between HOVlanes and ramp metering
Identifies need forestimatingdisaggregate mode-specific emissionfactors, includingvehicle fleetcharacteristics, andidentifies difficulties indoing so
Interrelationshipsbetween HOV lanesand ramp metering
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High-OccupancyVehicleFacilities(cont.)
Comparisonand analysis ofother studies(cont.)
"The Effect of HOVLanes in ReducingEmissions." Bieberitz,John A. ITE 1993Compendium ofTechnical Papers.
Describes andassessesanalyses ofseveral HOVdemonstrationprojects to informestimates of aHOV lane use inthe Milwaukeearea
Compares data fromdemonstration projects inseveral cities
Estimates include trafficgrowth rates
Does not provide cost-effectiveness of HOVlanes
Assumes HOV lanesare constructed on allsegments of thefreeways in theMilwaukee area
Traffic growth rates dac
IntelligentTransporta-tion Systems
Integratedplanning/simulationmodel
Combines thestrengths ofregionaltransportationplanning modelsand trafficsimulation models
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires verydetailed input data
Requires complexcomputer model
Potentially high costto use
"IntelligentTransportation SystemsImpact AssessmentFramework: FinalReport." VolpeNational TransportationSystems Center,September 30, 1995
Describesdevelopment andapplication of ananalytical tool topredict ITSimpacts, with afocus onAdvanced TrafficManagementSystems
Model integratestransportation planningand traffic simulation inan iterative fashion, andincludes emissions andfuel consumptionmodules
Report describes use ofmodel to analyze thepotential use of ITS in theI-880 corridor in AlamedaCounty, California,modeling ramp metering,traffic signal coordination,integrated trafficmanagement, incidentmanagement, and HOVlanes
Emissions module usesaccepted EMFAC andMOBILE factors
Relatively high costand complexity
Locally specific inputdata makes the I-880results of limited use inother areas
OperationalMeasures ofEffectiveness: VMT,traffic volume,average vehiclespeed, vehicle hoursof delay, fuelconsumption
Emission Measuresof Effectiveness: CO, HC, NOx
Safety Measures ofEffectiveness: personal injurylevels, propertydamage, totalaccidents
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IntelligentTransporta-tion Systems(cont.)
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requirescomplicatedcomputer model
Potentially high costto use
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel to modelVT, VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuses standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
"Travel, Emissions, andConsumer Benefits ofAdvanced TransitTechnologies in theSacramento Region." Johnston, Robert andRodier, Caroline. University of California,Davis. California PATHResearch Report, July1996.
UsescomprehensiveSacramentoRegional TravelDemand Model(SACMET 95) toestimate thepossible futureimpact of ITS ontravel mode,emissions, andconsumer welfare
Appendices providethorough explanation ofmodeling equations,assumptions andvariables
Explores interrelationsbetween income leveland consumer welfare
Model is not integratedwith a land use model;effects of majorchanges intransportation networkare not taken inaccount
Use of the modelrequires local inputparameters to forecastlocal effectiveness
More research isnecessary to generateuseful results
Vehicle miles andtotal hours traveled
Hours of delay andfree flow
Transportation modesplit: singleoccupant sharedride, transit, walk,bike
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IntelligentTransporta-tion Systems(cont.)
Vehiclequeuing model
Calculates vehicledelay and vehiclespeeds, to whichemission factorscan be applied
Applicable to anyroadway orroadway type
Analyst can varyinput parameters
Relatively low costto use
Queuing model istheoretical in naturerather than empirical
It is difficult to checkresults of theoreticalITS studies againstempirical results dueto the relatively lowcurrent level of ITSdeployment
Requires computermodel
Requires manysimplifyingassumptions
"Methodology forEvaluating ATISImpacts on Air Quality." Al-Deek, H. et al. Journal ofTransportationEngineering, vol. 121,no. 4, Jul/Aug 1995, pp.376-384.
Presents ananalytical methodfor evaluating theemissions impactof rerouting trafficguided with ATIS(using adeteriministicqueuing model),and applies themethod to asimple network. Evaluates CO,VOC, and NOximpact.
Uses MOBILE5aemission factors toestimate CO, VOC, andNOx impacts
Estimates impacts ofATIS at different levels ofmarket penetration and indifferent years
Can be applied to simpleor complex roadnetworks
Does not account fortransient emissionsassociated withacceleration
ATIS marketpenetration level
Road networkcharacteristics
Traffic incidentcharacteristics
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Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasuress
Case study resultsdo not necessarilyapply to otherregions
"EnvironmentalConsiderations forPlanning AdvancedTraffic ManagementSystems." Kraft,Walter H., and WilliamA. Redl, in ResourcePapers for the 1994ITE InternationalConference, 1994.
Reviewsenvironmentalfactors related toITS strategies,and presents acase study ofNew Jersey DOTI-80 MetropolitanArea GuidanceInformation andControl (MAGIC)project
Combines generaldiscussion with casestudy results from anactual ITS project
Evaluates changes inVMT and emissions (CO,HC, and NOx) at thecorridor level
Includes cost/benefitanalysis results
Tracks changes in VMTand emissions impactsover time
Emissions calculationmethodology andresults not presentedin great detail
Land use andphysical features
Emissions (CO, HC,NOx)
Benefit/cost ratio
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IntelligentTransporta-tion Systems(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects (cont.)
"ITS Benefits: Continuing Successesand Operational TestResults." Prepared byMitretek Systems forFederal HighwayAdministration. Draft,September 19, 1997.
Highlights existingand predicted ITSbenefits identifiedfrom a variety ofITSimplementationprograms,focusing on U.S.DOT-funded FieldOperational Testsand otherprogramsresulting fromrecent federalinitiatives
Reports benefits from avariety of projectscovering a variety of ITStechnologies
Includes ITS benefitsrelated to safety, time,throughput, cost,customer satisfaction,energy, and environment
Describes quantifiedemissions impacts forprojects in Seattle,Boston, Oklahoma, NewJersey, Los Angeles, andAbeline (Texas)
Includes exampleemissions results forAdvanced TravelerInformation Systems,electronic toll collection,and traffic signal systems
Reports results butdoes not showanalysis methods orcalculations
Not all reported resultshave been validatedfor completeness andreliability
Varies depending onproject summarized,but can include: VMT, vehicle trips,vehicle speeds, fuelusage, emissions(HC, CO, Nox)
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
The relatively lowcurrent level of ITSdeployment makesvalidation of sketchplanning resultsdifficult
Requires manysimplifyingassumptions
"Potential Emission andAir Quality Impacts ofIntelligent Vehicle-Highway Systems." Ostria, Sergio, andMichael F. Lawrence. In TransportationResearch Record 1444,1994.
Discusses short-term and long-term impacts ofITS technologybundles on trips,mode split, andemissions at aregional andcorridor level
Provides a broad initialassessment of theexpected direction ofimpact (positive,negative, insignificant,uncertain) of ITS bundleson travel behavior andemissions (HC, CO,NOx)
Utilizes solid a priorireasoning to predictimpacts
Discussion istheoretical rather thanempirical
Does not estimate themagnitude of travel oremissions impacts
Evaluates ITStechnology bundlesrather than individualITS technologies orITS-related policyoptions
Traffic flow
Vehicle trips
Trip distance
Mode shifts
Emissions (HC, CO,NOx)
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IntelligentTransporta-tion Systems(cont.)
Sketchplanning (cont.)
"Potential Contributionsof intelligentVehicle/HighwaySystems (IVHS) toReducingTransportation'sGreenhouse GasProduction." Shladover, Steven E. PATH, Institute ofTransportation Studies,U.C. Berkeley. August1991.
Identifies role ofITS in affectingtravel demandand supply andcategorizessubtypes of ITS
Good categorization ofvarious subtypes of ITS
Identifies clearly how ITSinfluences short-termtravel patterns andreduces traffic incidents
Provides littlequantification of VMTand delay reductions,no emissionsreductions
Inconclusive evidencefor effect ongreenhouse gases,since long-term effectsof ITS are unknown
Several subtypes ofITS
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"Assessing theEmission Impacts ofIVHS in an UncertainFuture." Washington,Simon P., RandallGuensler, and DanielSperling. University ofCaliforniaTransportation Center. Working Paper UCTCNo. 298, 1993.
Summarizes thelikely impacts ofthree ITStechnologybundles(Advanced TrafficmanagementSystems,AdvancedTraverlerInformationSystems, andAdvanced VehicleControl Systems)under differentsets of currentand futureassumptions
Provides background forevaluating a range ofemissions impacts of ITS
Assesses potentialchanges in ITSemissions impacts due tofuture changes in vehiclefleet composition anddriver behavior
Highlights potentialsynergies among ITStechnologies and policyoptions
Does not addressspecific policies orprograms that wouldimpact vehicle fleetcomposition and driverbehavior
Assesses theexpected direction, butnot the magnitude, ofITS emissions impacts
Does not draw upondata from specificexisting ITS projects
Travel impacts
Emissions impacts
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IntelligentTransporta-tion Systems(cont.)
Sketchplanning (cont.)
"Emissions Impacts ofIntelligent VehicleHighway Systems." Washington, Simon,Randall Guensler, andDaniel Sperling. U.C.Davis Institute ofTransportation Studies,UCD-RP-13-93. 1993.
A preliminaryassessment ofemissionsimpacts of ITStechnologybundles
Provides framework forevaluating emissionsimpacts of ITS
Discusses potential ITSimpacts of VMT, trip-endemissions, engine idling,diurnal and refuelingemissions, and modalemissions activity
Identifies role of ITS inreducing emissionsimpacts associated withnon-recurrent trafficcongestion
Addresses potential roleof ITS technologies inimplementing demandmanagement strategiessuch as congestionpricing and preferentialtreatment of sharedmodes
Assesses theexpected direction, butnot the magnitude, ofITS emissions impacts
Does not draw upondata from specificexisting ITS projects
VMT
Vehicle trips
Modal emissionsactivity
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Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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IntelligentTransporta-tion Systems(cont.)
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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"An Assessment ofIVHS-APTSTechnology Impacts onEnergy Consumptionand Vehicle Emissionsof Transit Bus Fleets." Jolibois, Sylvan C. Jr.,and Adib Kanafani. California PATHResearch Report. August 1994.
Examines thepotential impactsof AdvancedPublicTransportationSystems (APTS)technologies interms of vehicleemissions, airquality, and fuelconsumptionthrough aresearch review,and makessubsequent policyrecommendations
Provides a qualitativeassessment of IntelligentVehicle-HighwaySystems technologies onair quality and energyconsumption in bothshort and long term
Presents review ofcertain APTS programareas, specifically transitoperations of motorizedbus fleets
Provides ratios of transitbus emissions to autoemissions (perpassenger and pervehicle) for HC, CO,NOx, and PM
Report does notcontain a methodologyfor quantification ofemissions fromspecific transportationmeasures
Emissions ratios maybe based on overlyoptimistic ridershipestimates
Impacts of AdvancedPublic TransportationSystems (APTS)technologies onvehicle emissionsand fuelconsumption
Smart Traveler,Smart Vehicle, andSmart Intermodalsystems
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Intermodal Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specifictransportationmeasure individually;programs of multipletransportationmeasures areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
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Local LandUse/UrbanDesign
Travel demand/mode choicemodel
State-of-the-artmethod ofanalyzingindividual travelbehavior
Model's structureand parametersoffer considerableinsight into whatfactors influencetravel modeselection, andtherefore can beused to evaluatedifferent scenariosand details inprogram design
Travel demandmodels can beused to evaluatecombinations oftransportationmeasures as wellas individualmeasures
Can be used toisolate the impactof land usechanges on atransportationnetwork,minimizing otherfactors such asothertransportationmeasures
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
Does not directlyprovide emissionsestimates
Precision of analysiswill depend onaccuracy of bothgrowth projectionsand estimates of"holding capacity" oftargeted householdand employmentgrowth transferzones
"The Effectiveness ofTransportation ControlMeasures in ReducingCongestion andImproving Air Quality." Loudon, William R., etal. JHK & Associates. Air & WasteManagementAssociation AnnualMeeting & Exhibition1993. AWMA 93-RP-149.05.
Describes adevelopedtransportationdemand modelthat integratesemissionscalculations;provides examplecalculations fromthe model
Model has a user manualthat leads the analyststep-by-step through theinput of data for regionspecific analyses
Contains extensive cost-effectiveness module
Can be used at eitherregional or a smaller areaor location
Includes exhaust andevaporative emissions
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient
Commute trip lengthreduction throughnew zoning controls
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"Testing the Impact ofAlternative Land UseScenarios Using aTravel DemandForecasting Model." Steiss, Todd Alan. Baltimore MetropolitanCouncil, TransportationPlanning Division. TransportationResearch Board Paper960898.
Used traveldemandforecasting modelsoftware toanalyze fourdifferent land usealternatives in theBaltimoremetropolitan area
Travel forecasting modelused was MINUTP, atypical and familiar modelto planning agencies inthe Baltimore region(thus no learning curve),and techniques forevaluating model outputhad already beenestablished
Study compared baselinetransit networkprojections and 1)Baltimore's long-rangeplan without TCMs, 2)Plan with TCMs, 3) landuse alternativesseparately and incomposite
Emissions can becalculated for each landuse alternative
More sophisticatedland use model notutilized due to timeconstraints
Emissions actuallycalculated forcomposite of land usealternatives only
VMT, VT, and transitridership
Land usealternatives: "InsideBeltway," "FixedTransit,""Community"development and acomposite scenario
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Local LandUse/UrbanDesign(cont.)
Conventionaltransportationplanningnetwork model
Can be used toisolate the effecton travel patternsof different streetlayouts forneotraditional andconventionalneighborhoods
Hypotheticalmodeling exercise;does not use actualperformance datafrom existingneotraditional andconventionaldevelopments
Models do notaccount for manyaspects of local landuse strategies, suchas mixed land uses,street characteristicslike street and lanewidth andlandscaping, anddifferences indevelopmentdensities andparking availability
Modeling analysis ofa local streetnetwork does notaccount forinteraction betweenneighborhood andregional travel
"ComparativeAssessment of TravelCharacteristics forNeotraditionalDesigns." McNally,Michael and SherryRyan. Institute ofTransportation Studies. In TransportationResearch Record 1400.
Evaluates theperformancedifferences of twohypotheticalstreet networksdesigned toreplicate aneotraditional anda conventionalsuburbancommunity;determines thatneotraditionalstreet networkscan improvetransportationsystemperformance
Uses generalized,hypotheticaltransportation networkdesigns in order togenerate broadconclusions rather thanlocalized network-specificconclusions
Examines effectneotraditional design hason reducing vehiclekilometers and vehiclehours traveled
Generates resultsconsistent with earlierfindings by others
To isolate the impact ofthe street layout, all otheraspects of the modeledcommunities are heldconstant
The study does notcalculate emissionsdirectly; transportationimpacts are measuredin terms of vehiclekilometers traveled,average trip lengths,and congestion onlinks and atintersections
Model does not takeinto account narrowerrights-of-way anddenser grid thatusually typifyneotraditionaldevelopments;assumed equal trade-off
Because hypotheticalsubarea is only 0.5square miles, manyassumptions need tobe made aboutexternal trips
Trip generation rates,other travelparameters, andfriction factors whichwere adopted from theCity of Irvine couldhave introduced someerror, as they weredeveloped for a studyarea larger than thatused in this exercise
Transportationsystems ofhypotheticalneotraditional andconventionalsubdivisions
Vehicle kilometerstraveled
Mean trip length bytrip type
Intersection capacityutilization (ICU)
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Local LandUse/UrbanDesign(cont.)
Statisticalanalysis offactorsaffecting travelbehavior
Utilizes actualdata from traveldiaries, surveys,and/or local andhouseholdcharacteristics
Relatively simpleapproach (doesnot requirecomputermodeling)
Some results mayhave applicabilityto other regions
Complexity ofrelationship betweentravel behavior andurban form canmake it difficult toachieve statisticallysignificant results
Causality can bedifficult to establish
Uncertainapplicability tomultiple regions (butcan be duplicated atmoderate cost, ifnecessary)
"A Micro-Analysis ofLand Use and Travel inFive Neighborhoods inthe San Francisco BayArea." Kitamura,Ryuichi, et al. Instituteof TransportationStudies, UC Davis. November, 1994.
Analyzes surveysof five Bay Areaneighborhoods; assesses impactof land usecharacteristicsand attitudes ontravel behavior
Utilizes actual surveydata from five differentneighborhoods forcomparison
Distinguishes betweenimpact of land usecharacteristics, attitudes,and income
Explores multiplevariables (householdsize, profession,environmental attitude,time pressure, etc.)
More research isnecessary to reachconclusions that areuseful to land useplanners
Diaries and surveysrequire time-intensive,methodical approach
Land usecharacteristics(access to transit,sidewalk/bikewayavailability, etc.)
Personal attitudesrelated toenvironment,mobility, etc.
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"Using ResidentialPatterns and Transit toDecrease AutoDependence andCosts." Holtzclaw,John. For NaturalResources DefenseCouncil, June 1994.
Evaluates theeffects ofneighborhoodcharacteristics(density, transitaccessibility,neighborhoodshopping, andpedestrianaccessibility) onhousehold vehicleownership andVMT, based ondata from 27neighborhoods inCalifornia.
Explores some keyrelationships betweenoften-overlookedneighborhoodcharacteristics and travelbehavior
Uses innovativetechniques to account fortransit accessibility,neighborhood shopping,and pedestrainaccessibility
Uses data from a widevariety of Californianeighborhoods, fromcentral city to suburbanfringe
Evaluates VMT perhousehold, but doesnot estimate emissionsimpacts directly
Study does notaccount for severalpotentially importantneighborhoodcharacteristics,including parkingavailability andproximity to the urbancenter
Results may not beapplicable outside ofCalifornia
Annual VMT perhousehold
Household vehicleownership
Neighborhoodcharacteristics(density, transitaccessibility,neighborhoodshopping, andpedestrianaccessibility)
Household income
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Local LandUse/UrbanDesign(cont.)
Statisticalanalysis offactorsaffecting travelbehavior (cont.)
"Effect of UrbanDevelopment Patternson TransportationEnergy Use." Cheslow,Melvyn D., and J. KevinNeels. InTransportationResearch Record 764,1980.
Addresses theinfluence of travelpatterns onenergy use, andanalyzes therelationshipsbetween thesetravelcharacteristicsand measures ofurban form
Analyzes actual trip datafrom a pooled sample ofinterview surveys in eightstandard metropolitanstatistical areas (SMSAs)nationwide
Focuses on variation infuel use betweendifferent neighborhoodsand metropolitan areas
Does not defineexactly how urbanstructure may affecttravel characteristics
Study sample includedfew metropolitanareas, and wastherefore unable topinpoint the urban-scale characteristicsthat distinguished thedifferent metropolitanregions
Study does not includemixed land-usescenarios, or walkingtrips in travelcharacteristicsanalyzed
Does not addresseconomic and socialcosts and feasibility ofimplementing changesin urban developmentpatterns
Land usecharacteristics
Household travelpatterns
Transportationenergy use
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"The Odds on TODs: Examining the Potentialof Transit-OrientedDevelopment in theSan Francisco BayArea." Luscher, Dan. Harvard University,April 1995.
Quantifies VMTimpact ofhypotheticaltransit-orienteddevelopmentsbased onregressionanalysis;estimates costsand benefits oftransit-orienteddevelopment;shorter versionappears inBerkeley PlanningJournal, vol. 9,1995.
Identifies keyrelationships betweenneighborhoodcharacteristics and totaltravel
Uses hypothetical transit-oriented developmentsthat are similar to actualdevelopments being built
Estimates a range oftravel impacts per transit-oriented development aswell as for the SanFrancisco Bay region asa whole
Does not estimateemissions impactsdirectly
Results assume verywidespreadimplementation oftransit-orienteddevelopment
Results may not beapplicable outside ofCalifornia
Annual VMT perhousehold
Household income
Neighborhoodcharacteristics(density, transitaccessibility,distance from centralbusiness district)
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Local LandUse/UrbanDesign(cont.)
Statisticalanalysis offactorsaffecting travelbehavior (cont.)
"Travel Behavior as aFunction of Accessi-bility, Land Use Mixing,and Land Use Balance: Evidence from the SanFrancisco Bay Area." Kockelman, Kara M. University of California,Berkeley. TRB970048.
Correlates landuse and travelbehaviordatabases for theSan FranciscoBay Area todetermine theimpact of landuse mix, balance,and accessibilityon travel patterns
Utilizes 1990 census andhectare-level land-usedescription data fromactual surveys foraccurate characterizat-ions of local populationsand land use zones
Develops descriptivedefinitions forcharacterizing land usedata (accessibility, mix,and balance) to moreaccurately determine theinfluence of land use ontravel behavior
Results may not beheavily influenced bylocal conditions
Similar data may notbe available in thesame format in otherareas
Results showelasticities of VMT,auto ownership, andpersonal vehiclechoice with respect toland use accessibility,mix, and balance, butdo not calculate VMTor emission reductionsfrom thesecharacteristics
Land use access-ibility, mix, andbalance
Income per house-hold member
Auto ownership
Household size
Job and populationdensity
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"An Assessment of theLand Use -Transportation Systemand Travel Behavior." McNally, Michael G.,and Anup Kulkarni. U.C. Irvine. TRB971120, January 1997.
Correlates landuse,socioeconomic,and travelbehaviordatabases forOrange Countyneighborhoods todetermine theimpact of landuse on travelpatterns
Uses comprehensive listof indices to evaluateneighborhoodcharacteristics (e.g.,population density,number of 3-wayintersections, etc.) andcluster them into 3distinct themes
Studied socioeconomicdemographics inconjunction with land usepatterns to determinewhich is more influentialon trip patterns
Cannot investigatecorrelation betweenhousehold income andchoice ofneighborhood theme
Quantifies only triprate and mode share
Neighborhoodnetworkcharacteristics
Socioeconomicdemographics
Land use types
Accessibility
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"Transit-OrientedDevelopment in theSun Belt." Messenger,Todd, and Reid Ewing. In TransportationResearch Record 1552,1996.
Determined theminimum housingand workplacedensity requiredto support a giventransit servicelevel in the DadeCounty, Floridaarea
Provides detailedequations used tocalculate results
Allows for interactiveeffects between variables
Utilizes traffic analysiszone data from theCensus
Accuracy may be veryregion-specific
Does not quantifytravel or emissionreductions
Residence and work-place density
Automobileownership
Rail availability
Parking charge
Roadway network
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Local LandUse/UrbanDesign(cont.)
Statisticalanalysis of theimpacts of landusecharacteristicsand TDMstrategies onmode choice
Use of PrincipleComponentsAnalysisgeneratedcompositevariables (groupsof land usecharacteristicswith similarimpacts)
Standard analysisof variance usingprinciplecomponentsallowedexamination of theeffects of land useand TDMincentivestrategies onmode choiceindividually and incombination.
Resultstransferable toother urban areasin terms of relativeranking ofimportance of theland use and TDMfactors analyzed.
Precise causalityand individualimpacts of factorssuch as transitavailability or urbandensity on modechoice cannot bemeasured due tolimitations of thedatabase
Potential for need toconduct extensivefield research todetermine land usecharacteristics ateach sample worksite.
Cannot be used todetermine land useand urban designcharacteristics'impact on a specificmode choice
"The Effects of LandUse and TravelDemand ManagementStrategies onCommuting Behavior:Final Report." Prepared by CambridgeSystematics, Inc. andDeakin, Harvey,Skabardonis, Inc. forthe U.S. Department ofTransportation,November 1994.
Develops anintegrateddatabase of landusecharacteristicsand traveldemandmanagement(TDM) strategies(for a sample ofemploymentlocations) todetermine thecombined impactsof TDM programs,land use, andurban design onemployee travelbehavior.
Added land use and siteinformation from fieldobservation to the"Regulation XV" datasetof the South Coast AirQuality ManagementDistrict (which includedaggregate employeetravel characteristics andemployer incentiveprograms)
Study conducted inLos Angeles County,and thus may be lessapplicable in moredense urban areaswith factors such ashigher average densityand transit service.
Did not addressresidential trip end ofcommute, middaytravel, or trip chainingas factors whichinfluence mode choice
To simplify acomplicated datacollection process,somewhat arbitraryindicators were usedfor assessment of asite's urban designand land usecharacteristics.
Land use and urbandesign of worksite
TDM incentivestrategies
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Local LandUse/UrbanDesign(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Identifies barriersto implementingtransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Land Use Regulationsto PromoteRidesharing: AnEvaluation of theSeattle Approach." McCutcheon, Melody,and Jeffrey Hamm. TransportationQuarterly, vol. 37 no. 4,1983.
Evaluates theeffectiveness ofdeveloper-basedland useregulations topromoteridesharing inSeattle's centralbusiness district
Identifies barriers toenforcing parkingmanagement practices atbusinesses; suggestsimprovements
Does not quantify trip,VMT, or emissionsreductions
Study was performedbefore significant dataexisted on theeffectiveness of thewhole program
Availability of nearbyparking
Developercooperation withrequirements
dac
Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"Transportation-RelatedLand Use Strategies toMinimize Motor VehicleEmissions: An IndirectSource ResearchStudy." Dagang,Deborah A. JHK &Associates, Inc. ForCalifornia AirResources Board. June1995.
Based upon areview of relevantliterature, casestudies, and atravel surveystudy, this reportrecommendscommunity-levelperformancegoals, andpresentsappropriatetransportation-related land usestrategies andimplementationmechanisms
Performance goals areexpressed as annual VTper household, annualVMT per household,modal shares, andestimated relatedvehicular emissions
Addresses differences incommunity type, as threeranges of performancegoals for urban andsuburban areas and tworanges of performancegoals for exurban/ruralareas are specified
Recommendedcommunity-widepackages oftransportation-relatedland use strategiesaddress difficulty ofquantifying reductions inVT and emissions fromindividual strategiesapplied separately or ona site-specific basis
Applicability ofperformance goals andstrategyrecommendations toregions outsideCalifornia limited bystudy's use of primarilyCaliforniancommunities casestudies and data
Performance goals,strategies, andimplementationmechanisms do notinclude considerationof cost-effectiveness
Performance goaldevelopment can notuse availableBURDEN activity data,as it is not specificenough to allowaccurate segmentationby type of communitywithin a metropolitanarea
Transportation-related land usestrategies
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Local LandUse/UrbanDesign(cont.)
Sketchplanning (cont.)
"Simple Methodologiesfor Quantifying VT andVMT Reductions fromTransportation Controland GrowthManagement Measuresfor Developing LocalTrip ReductionOrdinances." Evans,V. and D. Morrow. Sonoma Technology,Inc. Air & WasteManagement Assoc. 1993
Describesdevelopment ofsimplemethodologies forquantifyingreductions invehicle trips (VT)and vehicle milestraveled (VMT)from TCMs, foruse in a planning-level context;specificallyanalyzespedestrianimprovements
Methods to quantify VTand VMT reductions fromTCMs were based uponrelatively simple methodsfor estimating emissionsand individual TCMeffectiveness developedprior to this report for theSouth Coast AQMD
Performance-basedapproach was developedrather than usemandated transportationperformance standards
Actual experience dataused as much aspossible: estimated tripreduction levels fromeach TCM was collectedfrom other studies, andplanning-level analysisuses site-specific datainputs, thus offeringincreased precision inemissions estimates
Ranges in VT reductionsestimates address theinteractive impacts of theapplication of multipleTCMs
Equivalency factor usedto convert VMT to VT canaccount for region-specific average triplengths
Expected reductions inVT and VMT fromTCMs were estimatedbased upon a generalsurvey, so for aparticular locationdifferent assumptionsmay be needed
Applicability to otherregions outsideCalifornia limited byreport's use oftransportation dataand emissions factorsin the analysis whichwere quantified usingBURDEN and EMFACruns for 1994
Does not incorporateany consideration ofcost-effectiveness
Employeeparticipation(percentage andfrequency)
Trip length
Existence/extent ofpedestrian pathsystem
Existence of showerfacilities
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Local LandUse/UrbanDesign(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
dac
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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Local LandUse/UrbanDesign(cont.)
Comparisonand analysis ofother studies(cont.)
"Transportation-RelatedLand Use Strategies toMinimize Motor VehicleEmissions: An IndirectSource ResearchStudy." Dagang,Deborah A. JHK &Associates, Inc. ForCalifornia AirResources Board. June1995.
Based upon areview of relevantliterature, casestudies, and atravel surveystudy, this reportrecommendscommunity-levelperformancegoals, andpresentsappropriatetransportation-related land usestrategies andimplementationmechanisms
Includes an extensiveliterature review matrixand annotatedbibliography summarizingquantifiable effectivenessdata of transportation-related land usestrategies in local,national, andinternational cases
Preliminary estimates ofindividual transportation-related land use strategyeffectiveness aredeveloped from theliterature review
Utilized as a resource anexisting detailedexamination of traveldata and transportationand land usecharacteristics inCalifornia (by JohnHoltzclaw for the NaturalResources DefenseCouncil, 1994)
Travel and land use datafrom selected Portland,Oregon, and Canadiancities were examined toprovide a basis ofcomparison for thecharacteristics found inthe Californian casestudies
Much of literature ontransportation-relatedland use strategiesdoes not containanalyses of modeledor empirical data, thussomewhat limitingscope of data included
Literature survey doesnot contain emissionsestimates, butsubsequent sketchplanning focuses onemissions related toVT and VMTperformance goals
Transportation-related land usestrategies
Land use andtransportationcharacteristics'impact on creationand support of publictransit systems andpedestrian-accessiblecommunities
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MarketIncentives
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requirescomplicatedcomputer model
Potentially high costto use
"Selection andEvaluation of TravelDemand ManagementMeasures." Taylor,Christopher J., et al. TRB 971114, January1997.
Uses TravelDemandEvaluation Modeldeveloped byCOMSIS toevaluate theimpact oftransportationmeasures onmode choice andVT for theSyracuse, NYmetropolitan area
Uses journey-to-workcensus data to developestimates of zone-to-zone travel
Evaluates both area-wideprograms and employer-based programs
Assesses revenuegeneration potential andtransit subsidies
Sufficiently detailedjourney-to-workcensus data may notbe available for allcities: Syracuse hasthis data available dueto a pilot program
Requires assumingsome estimates ofeffectiveness
Does not quantifyemissions reductions
Transit fare levelsand travel time
HOV lane timesavings
Parking costs
Employer transitencouragement level
dac
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel to modelVT, VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuses standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
Sample surveyof customertravel patternsandpreferences atshoppingcenters
Somewhatapplicable tomultiple regions(but influenced bylocal factors of thestudy area)
Does not requirean extensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
Moderate to highcost
"Analysis of IndirectSource Trip Activity: Regional ShoppingCenters." Prepared byJHK & Associates andK.T. Analytics for theCalifornia AirResources Board. ARB-R-94/510,November 1993.
Surveyedcustomers ofregional shoppingcenters todeterminepotential impactof various travelreductionmeasures
Uses actual survey data(including customerdemographic and statedpreference data)
Developed calculationmethodologies specific toeach trip reductionmeasure, using site-specific data
Compares data betweenshopping centers indifferent land-use types
Assumptions arerequired to translatestated preference datato expected outcome
Does not quantifyemission reductions
Transitsubsidy/validation
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MarketIncentives(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
dac
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"ManagingTransportationDemand: MarketsVersus Mandates." Giuliano, Genevieve,and Martin Wachs. Reason Foundation. Policy Insight No. 142,September 1992.
Comparescongestion pricingwith RegulationXV for theSouthernCalifornia area;describes prosand cons of eachmeasure anddiscussesimplications
Provides typology oftransportation measuresand identifies effective-ness and common bar-riers to implementation
Simple side-by-sidecomparison of VMTreduction and cost-effectiveness for eachtransportation measure
Makes policyrecommendations toimprove eachtransportation measure
Provides little detailabout logistics ofimplementing thepolicyrecommendations
Does not quantifyemission reductions
Direct vs. indirectimplementation
Market-based vs.performance-basedimplementation
Efficiency and equityconsiderations
dac
"The Equity and CostEffectiveness ofEmployee CommuteOptions Programs." Farkas, Z. Andrew. Morgan StateUniversity. TRB960078, January 1996.
Analyzes theresults of surveysand transportationmeasuremodeling studiesperformed for theBaltimore andPhiladelphiaregions
Shows different methodsof using the same model: Travel DemandEvaluation Modeldeveloped by COMSIS
Provides a discussion ofsocial equity considera-tions based on a surveyof the two regions
Philadelphia modelingassumed averagevehicle ridership tar-gets were reached andresults are only applic-able relative to eachscenario
Baltimore modeling didnot estimate emissionsreductions
Rideshare promotionlevel
Parking charge level
Transit subsidylevels
Work scheduleflexibility
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ParkingPricing/ParkingManagement
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Transportation PricingStrategies forCalifornia: AnAssessment ofCongestion, Emissions,Energy and EquityImpacts." California AirResources Board, June1995. Report No. 92-316.
Develops anduses acomprehensivetravel demandmodel to estimatethe impacts ofmultipletransportationmeasures
Uses actual, availableprice elasticities
Establishes base case bycomparing to actualtravel data
Explores interrelationsbetween pricingstrategies
Does not contain ahighway-networkmodel to include level-of-service changes
Forecasts rely onestimations ofchanges in householdtravel data
Price level, periodand location ofapplication
Price elasticity
Interrelationshipsbetween pricingstrategies
dac
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Fee level dac
"The Effectiveness ofTransportation ControlMeasures in ReducingCongestion andImproving Air Quality." Loudon, William R., etal. JHK & Associates. Air & WasteManagementAssociation AnnualMeeting & Exhibition1993. AWMA 93-RP-149.05.
Describes adevelopedtransportationdemand modelthat integratesemissionscalculations;provides examplecalculations fromthe model
Model has a user manualthat leads the analyststep-by-step through theinput of data for regionspecific analyses
Contains extensive cost-effectiveness module
Can be used at eitherregional or a smaller areaor location
Includes exhaust andevaporative emissions
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient
Fee level duringcommute trip parkingtimes
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ParkingPricing/ParkingManagement(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasure AnalysisProcedures." Austin,Barbara S., et al. Systems ApplicationsInternational/CaliforniaAir Resources Board.Nov 1991. SYSAPP-91/141.
Describes adevelopedtransportationdemand modeland explicitlydiscusses thecalculationmethodologyused for severaltransportationmeasures
Model quantifies keysecondary effects ofTCMs (e.g. newcarpooling programs mayattract transit ridersrather than SOV riders)
Presents all the primaryequations and variablesused to calculate theeffects of TCMs
Contains a step-by-stepprocess for evaluatingpackages of TCMs
Explains multi-attributeanalyses as applied tomultiple TCM packages
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient;participation level datais required; basecases need to matchreal conditions
Model does not coverall TCMs, but can bemodified to do so
Temporal treatment islimited to on-peak/off-peak, no spatialtreatment
Emissions calculationsare not explicitlydescribed in the samefashion as traveleffects
Level of peopleaffected by parkingmeasures
Availability ofspillover parking
Interaction withrideshare & transitprograms
Price level
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ParkingPricing/ParkingManagement(cont.)
Travel demand/mode choicemodel (cont.)
"A Survey and Analysisof EmployeeResponses toEmployer-SponsoredTrip ReductionIncentive Programs." Schreffler, Eric N., andMortero, Jose.COMSIS Corp.California AirResources Board,February 1994. Contract No. A983-187.
Describes resultsof new surveydata regardingemployee travelbehavior; usesmode choice andtravel demandmodel to predictimpacts of certainemployer-basedtransportationmeasures
Clearly explains theprocess that was used:survey data acquisition,mode choicecomputation, and TCMeffectiveness model use
Data requirements aremore readily availablethan other models
User-friendly model isavailable for outside use;users guide is alsoavailable
Survey links incentivesdirectly to impacts ontravel behavior
Model includes anawareness sub-modelthat simulates how manypeople know about thepossible TCMs availableto them
Does not accuratelyaddress trip-chainingand VMT reductions(only trips)
Household conditionsare not extensivelyaccounted for
Cost-effectivenesswas not calculated
Employer-levelanalyses only, withfocus upon incentiveTCMs
Guaranteed ridehome
Company vanpools
Preferential parking
Parking fees forridesharers
Carpool subsidies &transportationallowances
dac
"Estimating the Traveland Parking DemandEffects of Employer-Paid Parking." Willson,Richard. UCTC No. 39,University of CaliforniaTransportation Center,Berkeley, 1992.
Uses amultinomial logitmodel to estimatethe influence ofemployer-paidparking on themode oftransportationused to theworkplace
Explains the mainvariables and equationsused to computeprobabilities
Includes impact ofcomplementarytransportation measuressuch as rideshareincentives and flextime
Data set notdeveloped for thisparticular modelingeffort and missing keyvariables such asvehicle availability perhousehold
Model mostly useful inmetropolitan areawhere parking marketis more developed
Transportation mode(solo, carpool, ortransit)
Cars per 100employees
Elasticity of demandfor each mode
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ParkingPricing/ParkingManagement(cont.)
Travel demand/mode choicemodel (cont.)
"Selection andEvaluation of TravelDemand ManagementMeasures." Taylor,Christopher J., et al. TRB 971114, January1997.
Uses TravelDemandEvaluation Modeldeveloped byCOMSIS toevaluate theimpact oftransportationmeasures onmode choice andVT for theSyracuse, NYmetropolitan area
Uses journey-to-workcensus data to developestimates of zone-to-zone travel
Evaluates both area-wideprograms and employer-based programs
Assesses revenuegeneration potential andtransit subsidies
Sufficiently detailedjourney-to-workcensus data may notbe available for allcities: Syracuse hasthis data available dueto a pilot program
Requires assumingsome estimates ofeffectiveness
Does not quantifyemissions reductions
Transit fare levelsand travel time
HOV lane timesavings
Parking costs
Employer transitencouragement level
dac
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel to modelVT, VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuses standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
"Transportation Pricingand Travel Behavior." Harvey, Greig W. InCurbing Gridlock: Peak-Period Fees toRelieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Overview paperon the effects oftransportationsystem pricing onactivity patternsand travelbehavior; someemissions results
Paper presents modelingresults from the SanFrancisco Bay AreaPricing Study using theSTEP model
Quantifies VMT, trips,fuel usage, ROG, CO,NOx, and CO2
Shows quantified traveland emissions modelingresults that correspond tospecific, clearly definedpricing proposals
Use of modeldeveloped for SanFrancisco Bay Areamay limit usefulness ofresults to other regions
Study acknowledgesthat the STEP modeldoes not accuratelyaccount for regionalgrowth or employmentallocation, and treatstime of day in asimplified way
VMT
Vehicle trips
Fuel usage
Emissions (ROG,CO, NOx, CO2)
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ParkingPricing/ParkingManagement(cont.)
Parking supplyand demandmodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires computermodel
Potentially high costto use
"Air Quality Offsets forParking." Loudon,William, et al. InTransportationResearch Record 1232,1992.
Develops anduses parkingsupply model fordowntownPortland toestimate COemissions
Uses observed price andtravel time sensitivities
Uses proven models oftravel behavior
Incorporates integratedCO emissions model
Requires parkingdatabase: number ofspaces, location, type,use patterns
Requires traveldatabase: time ofarrival, trave & workmode split
Price level dac
Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
Not described dac
"Reducing Drive-AloneRates at SmallEmployer Sites: Costsand Benefits of LocalTrip ReductionOrdinances: PasadenaTowers Case Study." Stewart, Jacqueline. InTransportationResearch Record 1433,1994.
Evaluates thecost effectivenessof a building-based tripreduction planimplemented incompliance to alocal ordinance inPasadena,California
Attitudinal surveyincludes the influences ofbuilding tenant companysize as well as scheduleand lifestyle ofemployees
Uses small data setstherefore results varywidely with thebehavior of a fewindividuals
Does not establish astandard to evaluateaverage vehicleridership resultsobtained
Results may not betransferable to otheremployer sites orregions
Does not quantifyemission impacts
Program cost anddistribution of cost
Benefits todeveloper, tenantsand city
Average vehicleridership
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ParkingPricing/ParkingManagement(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Identifies barriersto implementingtransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specifictransportationmeasure individually;programs of multipletransportationmeasures areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
dac
"Land Use Regulationsto PromoteRidesharing: AnEvaluation of theSeattle Approach." McCutcheon, Melody,and Jeffrey Hamm. TransportationQuarterly, vol. 37 no. 4,1983.
Evaluates theeffectiveness ofdeveloper-basedland useregulations topromoteridesharing inSeattle's centralbusiness district
Identifies barriers toenforcing parkingmanagement practices atbusinesses; suggestsimprovements
Does not quantify trip,VMT, or emissionsreductions
Study was performedbefore significant dataexisted on theeffectiveness of thewhole program
Availability of nearbyparking
Developercooperation withrequirements
dac
Transportationsurvey analysis
Somewhatapplicable tomultiple regions(but influenced bylocal factors of thestudy area)
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process
"Cashing OutEmployer-Paid Parking: A Precedent forCongestion Pricing?" Shoup, Donald.University of California,Los Angeles, 1994. Contained inTransportationResearch Board SR242.
Usestransportationsurvey data toassess vehicletrip, VMT, andfuel use changesif cash paymentswere madeavailable toemployees in lieuof subsidizedparking
Uses actualtransportation behaviordata for the Los Angelesregion in addition toavailable supplementarydata
Requires only simplecalculations
Provides rebuttals toarguments against cashpayments
Requires care wheninferring applicability ofresults to other regions
Value of parkingsubsidy
Level of cashpayments in lieu ofparking subsidy
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ParkingPricing/ParkingManagement(cont.)
Transportationsurvey analysis(cont.)
"Analysis of IndirectSource Trip Activity: Regional ShoppingCenters." Prepared byJHK & Associates andK.T. Analytics for theCalifornia AirResources Board. ARB-R-94/510,November 1993.
Surveyedcustomers ofregional shoppingcenters todeterminepotential impactof various travelreductionmeasures
Uses actual survey data(including customerdemographic and statedpreference data)
Developed calculationmethodologies specific toeach trip reductionmeasure, using site-specific data
Compares data betweenshopping centers indifferent land-use types
Assumptions arerequired to translatestated preference datato expected outcome
Does not quantifyemission reductions
Parking fee level
Amount of othernearby parking
Proximity of potentialhigh-occupancypreferred parking
dac
Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasure effective-ness at low cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"TCM Analyst 1.0 andUser's Guide." Crawford, Jason A., etal. TexasTransportation Institute. For the FederalHighwayAdministration,November 1994.
Describes acomputerizedsketch planningtool, TCM Analyst1.0, includinginput datarequirements,methods of use,and an overviewof the model'sstructure andcalculationprocedures
Provides a useful andrelatively easy instructionmanual for using TCMAnalyst 1.0
Uses MOBILE5a outputdata (emission factors)as inputs to the model,providing more accurateemission benefitcalculations for eachTCM
Program only modelslimited TCMs andcannot model multipleTCM packages
Requires several runswith MOBILE5a toobtain input emissionfactors
Modeling on regional(rather thanmicroscale) basis only
Not stated dac
"Critical Analysis ofSketch-Planning Toolsfor Evaluating theEmission Benefits ofTransportation ControlMeasures." Crawford,Jason A., andRaymond A. Krammes. Prepared by TexasTransportation Institutefor FHWA, FHWA/TX-92/1279-5. December1993.
Critical analysisand sensitivityanalysis (usingdata for El Paso,Texas) of SanDiego Associationof Governments(SANDAG) TCMTools method andthe SystemsApplicationsInternational (SAI)method;summarized inTRR 1472
Provides a thoroughreview of the state of thepractice (as of 1993)
Identifies weaknesses inthe SANDAG and SAImethods as well asstrengths
Provides detailed sketch-planning analysis for ElPaso, Texas
Many of the inputs tothe SANDAG and SAImodels are difficult toquantify
The SANDAG and SAImodels do not fullyaccount for indirectimpacts and latenttravel demand
Vehicle trips
VMT
Average vehiclespeed
Emissions (HC, CO,NOx)
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ParkingPricing/ParkingManagement(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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ParkingPricing/ParkingManagement(cont.)
Comparisonand analysis ofother studies(cont.)
"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relativeeffectiveness ofvarioustransportationmeasure programs
Implementationmechanisms
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"Parking Subsidies andTravel Choices: Assessing theEvidence." Willson,Richard W. and DonaldC. Shoup. InTransportation, vol. 17,1990.
Reviews empiricalcase studies ofthe relationshipbetweenemployer-paidparking and solocommuting
Draws out analogousresults from a variety ofexisting case studies toshow range of impacts ofemployer-paid parkingand solo driving
Case studies cover avariety of locations(downtown andsuburban), employertypes (public and private)and employee categories(professional and clerical)
Case study results arereinforced by surveyfindings cited in the paper
Provides an estimatedrange for the elasticity ofdemand for solo drivingwith respect to parkingprice
Because most casestudies are from LosAngeles, results maynot be representativeof other areas
Range of results isvery wide, so theresults cannot directlybe used to accuratelyestimate the impactsof another program
Does not quantify VMTor emissions impacts
Existence ofemployer-paidparking
Travel mode (solodriver, non-solodriver)
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ParkingPricing/ParkingManagement(cont.)
Comparisonand analysis ofother studies(cont.)
"The Equity and CostEffectiveness ofEmployee CommuteOptions Programs." Farkas, Z. Andrew. Morgan StateUniversity. TRB960078, January 1996.
Analyzes theresults of surveysand transportationmeasuremodeling studiesperformed for theBaltimore andPhiladelphiaregions
Shows different methodsof using the same model: Travel DemandEvaluation Modeldeveloped by COMSIS
Provides a discussion ofsocial equityconsiderations based ona survey of the tworegions
Philadelphia modelingassumed averagevehicle ridershiptargets were reachedand results are onlyapplicable relative toeach scenario
Baltimore modeling didnot estimate emissionsreductions
Rideshare promotionlevel
Parking charge level
Transit subsidylevels
Work scheduleflexibility
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"Transportation Pricingand Travel Behavior." Harvey, Greig W. InCurbing Gridlock: Peak-Period Fees toRelieve TrafficCongestion. Vol. 2. TransportationResearch BoardSpecial Report 242,1994.
Overview paperon the effects oftransportationsystem pricing onactivity patternsand travelbehavior; someemissions results
Paper reviews empiricalresults and anecdotalfrom severaltransportation pricingprojects and studies
Review of existing resultsfocuses on aggregatedemand elasticity
Wide variability ofresults reviewed limitstheir usefulness
Aggregate demandelasticity
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RegionalLand Use/GrowthManagement
Conventionaltransportationplanningnetwork model
Can be used toisolate the effecton travel patternsof different landuse patterns
Hypotheticalmodeling exercise;does not use actualperformance datafrom existingneighborhoods
Models do notaccount for manyaspects of land usestrategies, such asmixed land uses,street characteristicslike street and lanewidth andlandscaping, anddifferences indevelopmentdensities andparking availability
Modeling analysis ofa local streetnetwork does notaccount forinteraction betweenneighborhood andregional travel
"The Impacts ofVarious Land UseStrategies on SuburbanMobility." MiddlesexSomerset MercerRegional Council(MSM). For theFederal TransitAdministration. December 1992.
Examines theinteractionbetweensuburban landuse trends andregional trafficconditionsutilizing threedifferent modelsof high density,mixed-usecenters; testedthe model'stransportationeffects on Trentonand NewBrunswicksuburban region
Used TransCADtransportation modelingpackage, whichincorporates land useelements in a GIS formatwith a traditional four-step transportationplanning model
Regional transportationmodel used to evaluateeffects of the 3 mixed-use centers (transit,short-drive, and walking)includes modeling of tripgeneration, distribution,mode split, and routeassignment
Regionwide tripmakingformulas concentratedon suburban practicesand do not provide agood reflection ofurban tripmakingconditions
Study does notcalculate emissionsdirectly; transportationimpacts are measuredin Vehicle Trips andVehicle Miles Traveled
Model assumes thatall new developmentlocates in cities or inhigher-density, mixed-use centers
Transportationeffects of suburban,higher density,mixed use centers,measured in: vehicle trips, level ofvehicle milestraveled, level ofdelay experienced,and average speed
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Statisticalanalysis offactorsaffecting travelbehavior
Utilizes actualdata from traveldiaries, surveys,and/or local andhouseholdcharacteristics
Relatively simpleapproach (doesnot requirecomputermodeling)
Some results mayhave applicabilityto other regions
Complexity ofrelationship betweentravel behavior andurban form canmake it difficult toachieve statisticallysignificant results
Causality can bedifficult to establish
Uncertainapplicability tomultiple regions (butcan be duplicated atmoderate cost, ifnecessary)
"Using ResidentialPatterns and Transit toDecrease AutoDependence andCosts." Holtzclaw,John. For NaturalResources DefenseCouncil, June 1994.
Evaluates theeffects ofneighborhoodcharacteristics(density, transitaccessibility,neighborhoodshopping, andpedestrianaccessibility) onhousehold vehicleownership andVMT, based ondata from 27neighborhoods inCalifornia.
Explores some keyrelationships betweenoften-overlookedneighborhoodcharacteristics and travelbehavior
Uses innovativetechniques to account fortransit accessibility,neighborhood shopping,and pedestrainaccessibility
Uses data from a widevariety of Californianeighborhoods, fromcentral city to suburbanfringe
Evaluates VMT perhousehold, but doesnot estimate emissionsimpacts directly
Study does notaccount for severalpotentially importantneighborhoodcharacteristics,including parkingavailability andproximity to the urbancenter
Results may not beapplicable outside ofCalifornia
Annual VMT perhousehold
Household vehicleownership
Neighborhoodcharacteristics(density, transitaccessibility,neighborhoodshopping, andpedestrianaccessibility)
Household income
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Rideshare Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Level of serviceprovided byemployer:information,matching services,preferential parking,ride home programs
Average vehicleridership
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"The Effectiveness ofTransportation ControlMeasures in ReducingCongestion andImproving Air Quality." Loudon, William R., etal. JHK & Associates. Air & WasteManagementAssociation AnnualMeeting & Exhibition1993. AWMA 93-RP-149.05.
Describes adevelopedtransportationdemand modelthat integratesemissionscalculations;provides examplecalculations fromthe model
Model has a user manualthat leads the analyststep-by-step through theinput of data for regionspecific analyses
Contains extensive cost-effectiveness module
Can be used at eitherregional or a smaller areaor location
Includes exhaust andevaporative emissions
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient
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Rideshare(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasure AnalysisProcedures." Austin,Barbara S., et al. Systems ApplicationsInternational/CaliforniaAir Resources Board.Nov 1991. SYSAPP-91/141.
Describes adevelopedtransportationdemand modeland explicitlydiscusses thecalculationmethodologyused for severaltransportationmeasures
Model quantifies keysecondary effects ofTCMs (e.g. newcarpooling programs mayattract transit ridersrather than SOV riders)
Presents all the primaryequations and variablesused to calculate theeffects of TCMs
Contains a step-by-stepprocess for evaluatingpackages of TCMs
Explains multi-attributeanalyses as applied tomultiple TCM packages
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient;participation level datais required; basecases need to matchreal conditions
Model does not coverall TCMs, but can bemodified to do so
Temporal treatment islimited to on-peak/off-peak, no spatialtreatment
Emissions calculationsare not explicitlydescribed in the samefashion as traveleffects
Effect of park andride lots
Formation of newversus existingcarpools
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Rideshare(cont.)
Travel demand/mode choicemodel (cont.)
"A Survey and Analysisof EmployeeResponses toEmployer-SponsoredTrip ReductionIncentive Programs." Schreffler, Eric N., andMortero, Jose.COMSIS Corp.California AirResources Board,February 1994. Contract No. A983-187.
Describes resultsof new surveydata regardingemployee travelbehavior; usesmode choice andtravel demandmodel to predictimpacts of certainemployer-basedtransportationmeasures
Clearly explains theprocess that was used:survey data acquisition,mode choicecomputation, and TCMeffectiveness model use
Data requirements aremore readily availablethan other models
User-friendly model isavailable for outside use;users guide is alsoavailable
Survey links incentivesdirectly to impacts ontravel behavior
Model includes anawareness sub-modelthat simulates how manypeople know about thepossible TCMs availableto them
Does not accuratelyaddress trip-chainingand VMT reductions(only trips)
Household conditionsare not extensivelyaccounted for
Cost-effectivenesswas not calculated
Employer-levelanalyses only, withfocus upon incentiveTCMs
Guaranteed ridehome
Company vanpools
Preferential parking
Parking fees forridesharers
Carpool subsidies &transportationallowances
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"Selection andEvaluation of TravelDemand ManagementMeasures." Taylor,Christopher J., et al. TRB 971114, January1997.
Uses TravelDemandEvaluation Modeldeveloped byCOMSIS toevaluate theimpact oftransportationmeasures onmode choice andVT for theSyracuse, NYmetropolitan area
Uses journey-to-workcensus data to developestimates of zone-to-zone travel
Evaluates both area-wideprograms and employer-based programs
Assesses revenuegeneration potential andtransit subsidies
Sufficiently detailedjourney-to-workcensus data may notbe available for allcities: Syracuse hasthis data available dueto a pilot program
Requires assumingsome estimates ofeffectiveness
Does not quantifyemissions reductions
Transit fare levelsand travel time
HOV lane timesavings
Parking costs
Employer transitencouragement level
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Rideshare(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel to modelVT, VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuses standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
Empiricalanalysis of theimpacts ofpersonalpreference andworkplaceconditions onmode choice
Somewhatapplicable tomultiple regions(but likely to beinfluenced heavilyby local factors ofthe study area)
Can be replicated(at moderate tohigh cost)
Does not requireextensivecomputer model
Uses actualsurvey data
Requires large datacollection process togenerate statisticallysignificant results
Personal preferenceand workplaceconditions difficult toimpact throughpublic policy
"Improving theEffectiveness ofRidesharing Programs." Stevens, William F. TransportationQuarterly, October1990. Vol. 44 No. 4.
Describes themethodology andresults of asurvey todetermine whichpersonalpreference andworkplace factorsaffect rideshareparticipation
Uses actual data from asurvey of current andpast rideshareparticipants as well as arandom sample ofpotential participants
Survey instrumentdeveloped through focusgroups and interviews forbetter results
Some findings mayhave beencontradicted by morerecent studies (e.g.,study finds that largecorporations havebetter success withrideshare programs)
Rideshare logisticsand personalflexibility
Monetary: parking,fuel
Interpersonal issues("having someone totalk to")
Altruism
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Rideshare(cont.)
Empiricalanalysis of theimpacts ofpersonalpreference andworkplaceconditions onmode choice(cont.)
"The Influence ofEmployer RidesharingPrograms on EmployeeMode Choice." Ferguson, Erik. Transportation, vol 17,1990.
Analyzesaggregate-leveldata compiled bya large SouthernCalifornia regionalridesharingagency; assessesimpact ofemployercharacteristics onemployee modesplit
Analyzes a large data setcomprising almost 10%of Los Angeles areaworkforce
Utilizing existing agencydatabase is a cost-effective approach
Less accurate thandisaggregated (employeeby employee) data
Includes cost-effectiveness estimations
Some findings mayhave beencontradicted by morerecent studies (e.g.,study finds that largecorporations havebetter success withrideshare programs)
Aging data source: 1985 survey data
Los Angeles areafactors may beuncharacteristic ofother regions, soresults may not beapplicable elsewhere
Employer-derived datawas acquired usingdifferent methods
No estimates ofemissions impacts
Level of employereffort to encourageridesharing
Size of firm
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Rideshare(cont.)
Empiricalanalysis of theimpacts ofpersonalpreference andworkplaceconditions onmode choice(cont.)
"The Effectiveness ofRidesharingIncentives." Brownstone, David,and Thomas F. Golob,in Regional Scienceand Urban Economics,vol. 22, 1992.
Evaluates thetravel impacts ofcertain incentivesdesigned topromoteridesharing(carpooling andvanpooling) onwork trips, usingdata from a studyof full-timeworkers'commutingbehavior in theLos Angeles area
Analysis is based on arich data set
Evaluates potentialimpact on ridesharing ofemployer-providedpreferential parking andHOV lanes
Provides insight intowhich householdcharacteristics andemployer characteristicsinfluence ridesharing
Does not directlyquantify VMT oremissions impacts
Conclusions may notapply to areas otherthan SouthernCalifornia
Mode choice (alwaysrideshare,sometimesrideshare, alwaysdrive alone)
Individualcharacteristics(income, age,gender)
Commutecharacteristics(distance, HOV laneavailable)
Employer incentives(flexible schedule,preferential parking,cost subsidy,guaranteed ridehome)
Employer size
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Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
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Rideshare(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms(cont.)
"The Los AngelesCounty Route 14Vanpool and BuspoolDemonstration Project: An Analysis of itsEffectiveness inReducing LongDistance CommuterTrips." Blanchard,Donna et al. TransportationResearch Board. July1993.
Addresses theeffectiveness of ademonstrationvanpool andbuspool project,an incentive-based programestablished torelieve congestionand improve airquality along theLos AngelesCounty Route 14corridor
Calculates the totalnumber of vehicle tripsand vehicle milestraveled reduced, byorigin and destination, ofprogram participants
Phase II follow-up projectto include computerizedtracking program anddata collection
Does not provideemissions estimates
Requires costlyadministration,tracking and datacollection efforts;participant programexit information oftenincomplete
Report does notcontain details ofparticipants' priormode choice orcommute length
Vanpool and buspoolincentives: riderrebate, child carebonus, andemergency(guaranteed) rideshome
Programparticipation
Cost-effectiveness
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Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Identifies barriersto implementingtransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specifictransportationmeasure individually;programs of multipletransportationmeasures areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
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"Land Use Regulationsto PromoteRidesharing: AnEvaluation of theSeattle Approach." McCutcheon, Melody,and Jeffrey Hamm. TransportationQuarterly, vol. 37 no. 4,1983.
Evaluates theeffectiveness ofdeveloper-basedland useregulations topromoteridesharing inSeattle's centralbusiness district
Identifies barriers toenforcing parkingmanagement practices atbusinesses; suggestsimprovements
Does not quantify trip,VMT, or emissionsreductions
Study was performedbefore significant dataexisted on theeffectiveness of thewhole program
Availability of nearbyparking
Developercooperation withrequirements
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Empiricalanalysis oftransportationmeasuredemonstrationprojects (cont.)
"Transportation-RelatedImpacts of CompressedWork Week: TheDenver Experiment." Atherton, Terry J., et al. In TransportationResearch Record 845,1982.
Provides beforeand aftercomparison oftravel behavior foran experimentalcompressed-workweek program forfederalemployees inDenver
Before-and-afterapproach (with a controlgroup) accuratelyassesses changes intravel
Utilizes actual traveldiaries and surveys totrack travel patterns
Identifies some non-worktravel impacts ofcompressed work weeks
Information was completeand accurate due togovernment workplacefocus
Private organizationsmay not respond aswell to requirements toimplementcompressed workweek plans
9/80 schedule vs.4/40 schedule
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Statisticalanalysis ofemployerridesharinginitiatives
Utilizes largedatabase ofexisting employersthat implementtransportationmeasures
Relatively low-cost(provided datadoes not need tobe collected)
May not assesscauses of statisticalsignificance found
Results notnecessarilyapplicable to otherregions
"Evaluation ofEmployer-SponsoredRidesharing Programsin Southern California." Ferguson, Erik T.,Georgia Institute ofTechnology. InTransportationResearch Record 1280,1990.
Analyzesdatabase ofsurveys ofemployer-sponsoredridesharingprograms inSouthernCalifornia todeterminerelevant factorson effectiveness
Utilizes large existingdatabase for the region,increasing validity ofresults
Assesses cost-effectiveness at varyingprogram sizes
Assesses interactionbetween alternative workschedules andridesharing
Attempts to explainreasons behind statisticalsignificance of certainfactors
Sample database maybe biased (they wereall clients of acentralized ridesharingagency)
Primarily analyzesemployer-basedmeasures only
Level and type ofdirect ridesharingincentives
Firm size and type
Dollars spent onrideshare programs
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Rideshare(cont.)
Samplesurveys
Uses statisticallyrepresentativesample populationto make estimatesof impact ofridesharingstrategies on theridesharingparticipation andeffectiveness
Sample size (andtherefore cost)can be variedbased on level ofstatisticalaccuracy desired
Surveys can bedone periodicallyto determinechanges inridesharing ratesover time, andimpacts of specialpromotions suchas "Try Transit"weeks
Surveys can entailsignificant costs
"Revolving door"characteristic ofridesharing programscan be difficult toaddress withaccuracy
Relationshipbetween ridesharingparticipation, VMT,and emissionsrequires additionalanalysis
If surveys areperformed differentlyin different regions,direct comparisonsof results may not bevalid
Survey results canbe subject to variouskinds of responsebias
"Rideshare PlacementMesurement: AProposed StandardMethodology." King,Michael, and BarbaraAlderson. CaliforniaState University atChico, June 1995.
Developsmethodology forquantifyingrideshareplacement levelsfor ridematchingservices;discusses pilottesting ofmethodology(note: thismethodology iscurrently used byRIDES for BayArea Commutersin the SanFrancisco BayArea).
Survey methodology isgeneric and can beapplied to any region
Methodologydistinguishes betweenthree types of rideshareplacements (trial,maintenance, andongoing) to reflect theirdifferent impact on traveland emissions
Only quantifiesrideshare placement;does not directlyquantify VMT andemissions impact
Rideshare placementrate (trial,maintenance, andongoing)
Survey responserate
Statistical samplingerror
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"Cost-Effectiveness ofPrivate EmployerRidesharing Programs: An Employer'sAssessment."Wegmann, Frederick J. University ofTennessee. InTransportationResearch Record 1212,1989.
Conducts andanalyzes samplesurveys with theaim ofdocumenting thecost and benefitsavailable toprivate-sectoremployersthrough theoperation ofemployerridesharingprograms
Survey methodology isgeneric and can beapplied to any region
Diverse study sampleincluded respondentsfrom throughout the U.S.,and representedcompanies in centralbusiness districts, withincity limits, and insuburbs, from a diversityof industry types
Only quantifiesrideshare cost-effectiveness toemployers; does notdirectly quantify VMTand emissions impact
Quantitative estimatesof ridesharing benefitsare very difficult tomake; therefore,further follow up with asubset of the samplesurveyed was requiredto convert generalestimates of benefitsinto annual monetaryvalues
Most benefits cited byrespondents were ofan intangible nature;therefore, the database necessary togenerate cost-benefitanalyses does notexist
Employer ridesharingcosts, includingvanpooling andvanpooling subsidycosts; employerparking costs
Ridesharing cost-effectiveness
Ridesharing benefits
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"TCM Analyst 1.0 andUser's Guide." Crawford, Jason A., etal. TexasTransportation Institute. For the FederalHighwayAdministration,November 1994.
Describes acomputerizedsketch planningtool, TCM Analyst1.0, includinginput datarequirements,methods of use,and an overviewof the model'sstructure andcalculationprocedures
Provides a useful andrelatively easy instructionmanual for using TCMAnalyst 1.0
Uses MOBILE5a outputdata (emission factors)as inputs to the model,providing more accurateemission benefitcalculations for eachTCM
Program only modelslimited TCMs andcannot model multipleTCM packages
Requires several runswith MOBILE5a toobtain input emissionfactors
Modeling on regional(rather thanmicroscale) basis only
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Rideshare(cont.)
Sketchplanning (cont.)
"Simple Methodologiesfor Quantifying VT andVMT Reductions fromTransportation Controland GrowthManagement Measuresfor Developing LocalTrip ReductionOrdinances." Evans,V. and D. Morrow. Sonoma Technology,Inc. Air & WasteManagement Assoc. 1993
Describesdevelopment ofsimplemethodologies forquantifyingreductions invehicle trips (VT)and vehicle milestraveled (VMT)from TCMs, foruse in a planning-level context; developedoriginally for theSouth Coast AirBasin
Methods to quantify VTand VMT reductions fromTCMs were based uponrelatively simple methodsfor estimating emissionsand individual TCMeffectiveness developedprior to this report for theSouth Coast AQMD
Performance-basedapproach was developedrather than usemandated transportationperformance standards
Actual experience dataused as much aspossible: estimated tripreduction levels fromeach TCM was collectedfrom other studies, andplanning-level analysisuses site-specific datainputs, thus offeringincreased precision inemissions estimates
Ranges in VT reductionsestimates address theinteractive impacts of theapplication of multipleTCMs
Equivalency factor usedto convert VMT to VT canaccount for region-specific average triplengths
Expected reductions inVT and VMT fromTCMs were estimatedbased upon a generalsurvey, so for aparticular locationdifferent assumptionsmay be needed
Applicability to otherregions outsideCalifornia limited byreport's use oftransportation dataand emissions factorsin the analysis whichwere quantified usingBURDEN and EMFACruns for 1994
Does not incorporateany consideration ofcost-effectiveness
Employeeparticipation(percentage andfrequency)
Employer trip-reduction plan
Distance to work
Distance to andexistence of Park-n-Ride lots
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Rideshare(cont.)
Sketchplanning (cont.)
"Evaluating Travel andAir Quality Cost-Effectiveness ofTransportation DemandManagement Projects." Schreffler, Eric N.,Therese Costa, andCarl B. Moyer. InTransportationResearch Record 1520,1996.
Describes simplemethodologiesused to evaluateprojects fundedby the AB 2766vehicleregistration feeprogram inSouthernCalifornia
Methodology can beused to evaluate priorprojects or proposedfuture projects
Uses available EMFACemission rates tocalculate ROG, PM10,NOx, and CO
Study developsstandardized worksheetto evaluate projects
Study points outdrawbacks of self-reported project results
Methodology relies onparticipation dataprovided by projectproponents, whichmay not always beunbiased
EMFAC7E factors areCalifornia-specific
Trips reduced
Trip length
Prior travel mode
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"Critical Analysis ofSketch-Planning Toolsfor Evaluating theEmission Benefits ofTransportation ControlMeasures." Crawford,Jason A., andRaymond A. Krammes. Prepared by TexasTransportation Institutefor FHWA, FHWA/TX-92/1279-5. December1993.
Critical analysisand sensitivityanalysis (usingdata for El Paso,Texas) of SanDiego Associationof Governments(SANDAG) TCMTools method andthe SystemsApplicationsInternational (SAI)method;summarized inTRR 1472
Provides a thoroughreview of the state of thepractice (as of 1993)
Identifies weaknesses inthe SANDAG and SAImethods as well asstrengths
Provides detailed sketch-planning analysis for ElPaso, Texas
Many of the inputs tothe SANDAG and SAImodels are difficult toquantify
The SANDAG and SAImodels do not fullyaccount for indirectimpacts and latenttravel demand
Vehicle trips
VMT
Average vehiclespeed
Emissions (HC, CO,NOx)
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Rideshare(cont.)
Employer TDMcost-effectivenessmodel
Estimatesreduction in andcosts of daily tripsand peak periodtrips
Aids employerdetermination ofcost-effectivenessof TDM measuresfor their particularworksite
Results may varywidely from oneemployer to the next
Many inputs may bedifficult foremployers orplanners to quantify
"TransportationDemand ManagementCost-EffectivenessModel for SuburbanEmployers." Dagang,Deborah A. JHK &Associates. InTransportationResearch Record 1404.
Reports on thedevelopment of amodel toindividuallyevaluate the cost-effectiveness of15 differentemployer-basedTDM measures insuburban settings
Focus on suburbanemployers reflectsdifferent travel-relatedcharacteristics ofsuburban and urbanareas
Spreadsheet-basedmodel is user-friendlyand readily accessible foruse at the site-specificlevel; model makessensitivity analysisrelatively simple
Eight transportationenvironments weredefined to representvarious combinations oftransportation servicecharacteristics
For employers withoutaccess to entire range ofdata necessary tooperate model, defaultvalues are included
Most employerssurveyed to developmodel were unable toprovide detailed costinformation on theTDM measures theyhad implemented
Does not calculateemissions directly
Potential for regionalbias, as model wasdeveloped in partbased on a survey ofsuburban SanFrancisco Bay Areaemployers; model alsoused the SCAQMDRegulation XV andPima Association ofGovernments TravelReduction Programemployer plandatabases
Only some TDMsincluded in modelprovide for estimatesof VT reductions
Use of default valuescould diminishesaccuracy of estimatesfor some users
Suburban employer-based TDMmeasures
Daily trips and peakperiod trips
Costs and cost-effectiveness
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Rideshare(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
dac
Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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Rideshare(cont.)
Comparisonand analysis ofother studies(cont.)
"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relativeeffectiveness ofvarioustransportationmeasure programs
Implementationmechanisms
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"Parking Subsidies andTravel Choices: Assessing theEvidence." Willson,Richard W. and DonaldC. Shoup. InTransportation, vol. 17,1990.
Reviews empiricalcase studies ofthe relationshipbetweenemployer-paidparking and solocommuting
Draws out analogousresults from a variety ofexisting case studies toshow range of impacts ofemployer-paid parkingand solo driving
Case studies cover avariety of locations(downtown andsuburban), employertypes (public and private)and employee categories(professional and clerical)
Case study results arereinforced by surveyfindings cited in the paper
Provides an estimatedrange for the elasticity ofdemand for solo drivingwith respect to parkingprice
Because most casestudies are from LosAngeles, results maynot be representativeof other areas
Range of results isvery wide, so theresults cannot directlybe used to accuratelyestimate the impactsof another program
Does not quantify VMTor emissions impacts
Existence ofemployer-paidparking
Travel mode (solodriver, non-solodriver)
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Rideshare(cont.)
Comparisonand analysis ofother studies(cont.)
"ManagingTransportationDemand: MarketsVersus Mandates." Giuliano, Genevieve,and Martin Wachs. Reason Foundation. Policy Insight No. 142,September 1992.
Comparescongestion pricingwith RegulationXV for theSouthernCalifornia area;describes prosand cons of eachmeasure anddiscussesimplications
Provides typology oftransportation measuresand identifies effective-ness and common bar-riers to implementation
Simple side-by-sidecomparison of VMTreduction and cost-effectiveness for eachtransportation measure
Makes policy recom-mendations to improveeach transportationmeasure
Provides little detailabout logistics ofimplementing thepolicyrecommendations
Does not quantifyemission reductions
Direct vs. indirectimplementation
Market-based vs.performance-basedimplementation
Efficiency and equityconsiderations
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"The Equity and CostEffectiveness ofEmployee CommuteOptions Programs." Farkas, Z. Andrew. Morgan StateUniversity. TRB960078, January 1996.
Analyzes theresults of surveysand transportationmeasuremodeling studiesperformed for theBaltimore andPhiladelphiaregions
Shows different methodsof using the same model: Travel DemandEvaluation Modeldeveloped by COMSIS
Provides a discussion ofsocial equity considera-tions based on a surveyof the two regions
Philadelphia modelingassumed averagevehicle ridershiptargets were reachedand results are onlyapplicable relative toeach scenario
Baltimore modeling didnot estimate emissionsreductions
Rideshare promotionlevel
Parking charge level
Transit subsidylevels
Work scheduleflexibility
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"The Determinants ofRidesharing: LiteratureReview." Hwang, Keithand GenevieveGiuliano. University ofCaliforniaTransportation Center,May 1990. UCTC 38.
Reviews dozensof studies in ageneraldiscussion ofridesharing
Integrates results andcitations of many papersin a clear description ofeach issue impactingridesharing, includingreasons for effectiveness
Describes effectivenessof programs, as well asemployee and workplacecharacteristics that arefavorable for ridesharing
Describes someinteraction between othertransportation measures(e.g., HOV facilities) andridesharing
Comments about eachstudy may be too briefto provide clearguidance for TCMplanning
Does not provide VMTor emissionsreduction, only modeshare data
Many are brieflytouched upon
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Scrappage Economicscrappagesupply curvemodel
A rigorousapproach basedon economicfundamentals
Allows analyst toestimatescrappageemissionsreductions forvarious levels of"bounty," which isa key programdesign element
Relatively low costto use
Models of thistype could beextended toevaluate impactsof othertransportationmeasures thatimpact oldervehicles, such asI/M and emissionsfees
Level of precisionmost applicable tosmall-scaleprograms, as modelsof this type usuallywill not capture priceeffects on the used-car market followingwithdrawal of a largefraction of theexisting old vehicles
Models of this typeare theoretical ratherthan empirical, andtherefore may notaccuratelycharacterizeparticipation ratesand other aspects ofreal-world behavior
Remaining life andusage of scrappedvehicles, as well asreplacement vehiclecharacteristics, arefundamentallydifficult to estimatewith precision
"An Economic Analysisof Scrappage." Hahn,Robert W. AmericanEnterprise Institute,July 1993.
Estimates thenumber and valueof old vehicles todetermine costsand benefits ofscrappageprogram
Uses availableEMFAC7E emissionrates
Uses available fleetcomposition figures
Uses available "GoldBook" vehicle valuefigures
Operating costs notincluded in economicassessment
EMFAC7E factors areCalifornia-specific
Assumes unknownhuman factors andbehaviors
Fleet composition
Vehicle "Gold Book"value
Replacement vehiclecharacteristics
Variable discountrates
Interaction with I&Mprograms
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"Estimating anEmissions SupplyFunction fromAccelerated VehicleRetirement Programs." Alberini, Anna et al. Resources for theFuture, January 1994.
Study developsmethodologywhich predictsparticipationrates, expectedremaining life,and an emissionssupply function atalternative offerprices for severaltypes of pre-1980s vehiclescrap programs
Analysis is based onextensive surveys of oldvehicle owners andvehicle emissions testingdata collected through aparticular scrappageprogram
Study develops empiricalmeasure of the linkbetween vehiclecondition and expectedremaining life, andowner's estimation ofvehicle value todetermine costs andemission reductionpotential of program
Study conducts surveysof participants and non-participants forinformation aboutremaining life and usageof scrapped vehicle
Survey data used isspecific to scrappageprogram in Delaware1992-93, so resultsmay not be applicableto other regions andprograms
Sample of ownerssurveyed did notrepresent a randomsample of thepopulation of pre-1980vehicle owners
Scope of data onemissions of scrappedvehicles is limited asonly a sample ofvehicles valued at lessthan the bountyamount offered weretested
Assumes thatscrapped vehiclereplacement is from"average" fleet interms of emissionslevels
Individual ownerbehavior andvehicle's remaininglife
Minimum willingnessto accept bountyamount; alsodetermined by bluebook value, conditionof car, and past andfuture costs ofoperating the car
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Scrappage(cont.)
Vehicle fleetcharacteri-zation andemissionsmodel
Utilizes standardplanning modelused by regulatoryagencies
High flexibility tomanipulate inputdata
Requires detailedunderstanding ofcomputer model'smethodologies andsource code
Results are notreadily applicable toother regions
Difficult and costly toreplicate
"Vehicle Scrappage: An Alternative to MoreStringent New VehicleStandards inCalifornia." Lyons,James, et al. SierraResearch. For TexacoInc. SR95-03-02. March 1995.
Modifies sourcecode forCalifornia-specificEMFAC/BURDENfleetcharacterizationand emissionsmodel to evaluatethe effect ofscrappageprograms onemissions in theSouth Coast AirBasin
Use of EMFAC/BURDENmakes analysis highlyconsistent with CaliforniaAir Resources Board'sfleet and emissionscharacterizations, whichhelps compare emissionsreductions to inventory
Allows considerableflexibility in testingspecific scrappagescenarios
Compares scrappagescenarios to otheremission reductionalternatives (e.g.,reduced standards)
Light-, medium-, andheavy-duty programsassessed
Does not incorporateactual elasticitiesbetween scrappagebounty and number ofvehicles scrapped(elasticities areassumed)
Age threshold forscrapped vehicles
Number of totalvehicles scrapped
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Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"Meeting Clean Air ActEmissions Standards: A Cost-EffectivenessAnalysis of CarScrappage." DeCardy,Christopher. HarvardUniversity, April 1994.
Compares 4studies onscrappage cost-effectiveness;proposes newscrappage studythat woulddevelop accurateinputs forcalculating cost-effectiveness
Provides severalestimates of cost-effectiveness from eachstudy
Identifies reasons why 4studies overestimatecost-effectiveness ofscrapping
Performing the proposedstudy would clarifyuncertainties in cost-effectiveness
Estimates may still betoo rough to apply toother programs inother regions
Does not identify allcosts and benefits ofscrappage programs
Does not addresspotential equityimpacts of scrappage
Analyzes only HCemissions
Outside factorsaffecting scrappageprograms (e.g I&Mprograms)
Levels of partipationin scrappageprograms
Sources of data (e.g.for emission rates,MOBILE vs. actualtesting)
Level of bountyoffered
Affect of scrappageprograms on marketforces
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"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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"Uncertain Air QualityImpacts of AutomobileRetirement Programs."Shi-Ling Hsu andDaniel Sperling. InTransportationResearch Record 1444,1995.
Identifies andanalyzes theareas ofuncertainty indeterminingemission impactsof scrappageprograms
Provides acomprehensive list ofparameters needed tocalculate the costeffectiveness of ascrappage program
Identifies the reasonswhy previous estimatesare inaccurate
Does not proposesuggestions to reduceuncertaintyencountered inprevious studies
Impacts of regionaldifferences are notthoroughly discussed
Average annualmileage andremaining life ofretired autos
HC, NOx and COemissions of retiredautos
Annual mileage ofreplacement autosand averageemissions
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Shuttles/Station Cars
Sample surveyof customertravel patternsandpreferences atshoppingcenters
Somewhatapplicable tomultiple regions(but influenced bylocal factors of thestudy area)
Does not requirean extensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
Moderate to highcost
"Analysis of IndirectSource Trip Activity: Regional ShoppingCenters." Prepared byJHK & Associates andK.T. Analytics for theCalifornia AirResources Board. ARB-R-94/510,November 1993.
Surveyedcustomers ofregional shoppingcenters todeterminepotential impactof various travelreductionmeasures
Uses actual survey data(including customerdemographic and statedpreference data)
Developed calculationmethodologies specific toeach trip reductionmeasure, using site-specific data
Compares data betweenshopping centers indifferent land-use types
Assumptions arerequired to translatestated preference datato expected outcome
Does not quantifyemission reductions
Availability of nearbytransit
Availability of nearbyrail
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"Evaluating Travel andAir Quality Cost-Effectiveness ofTransportation DemandManagement Projects." Schreffler, Eric N.,Therese Costa, andCarl B. Moyer. InTransportationResearch Record 1520,1996.
Describes simplemethodologiesused to evaluateprojects fundedby the AB 2766vehicleregistration feeprogram inSouthernCalifornia
Methodology can beused to evaluate priorprojects or proposedfuture projects
Uses available EMFACemission rates tocalculate ROG, PM10,NOx, and CO
Study developsstandardized worksheetto evaluate projects
Study points outdrawbacks of self-reported project results
Methodology relies onparticipation dataprovided by projectproponents, whichmay not always beunbiased
EMFAC7E factors areCalifornia-specific
Trips reduced
Trip length
Prior travel mode
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Shuttles/Station Cars(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Telecom-muting
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
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Telecom-muting(cont.)
Travel demand/mode choicemodel (cont.)
"The Effectiveness ofTransportation ControlMeasures in ReducingCongestion andImproving Air Quality." Loudon, William R., etal. JHK & Associates. Air & WasteManagementAssociation AnnualMeeting & Exhibition1993. AWMA 93-RP-149.05.
Describes adevelopedtransportationdemand modelthat integratesemissionscalculations;provides examplecalculations fromthe model
Model has a user manualthat leads the analyststep-by-step through theinput of data for regionspecific analyses
Contains extensive cost-effectiveness module
Can be used at eitherregional or a smaller areaor location
Includes exhaust andevaporative emissions
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient
Participation levels dac
"Transportation ControlMeasure AnalysisProcedures." Austin,Barbara S., et al. Systems ApplicationsInternational/CaliforniaAir Resources Board.Nov 1991. SYSAPP-91/141.
Describes adevelopedtransportationdemand modeland explicitlydiscusses thecalculationmethodologyused for severaltransportationmeasures
Model quantifies keysecondary effects ofTCMs (e.g. newcarpooling programs mayattract transit ridersrather than SOV riders)
Presents all the primaryequations and variablesused to calculate theeffects of TCMs
Contains a step-by-stepprocess for evaluatingpackages of TCMs
Explains multi-attributeanalyses as applied tomultiple TCM packages
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient;participation level datais required; basecases need to matchreal conditions
Model does not coverall TCMs, but can bemodified to do so
Temporal treatment islimited to on-peak/off-peak, no spatialtreatment
Emissions calculationsare not explicitlydescribed in the samefashion as traveleffects
Work and non-worktrip increases by thetelecommuter andother householdmembers
Satellite centers
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Telecom-muting(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms
Analyzes actualtelecommutingprograms
Addresses travelbehavior patterns
Does not requireextensivecomputer model
Applicability ofresults to otherregions andconditions isuncertain
Is not likely toaddress totaldemand fortelecommuting
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
Not described dac
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasuress
Case study resultsdo not necessarilyapply to otherregions
"Impacts of Center-Based Telecommutingon Travel andEmissions: Analysis ofthe Puget SoundDemonstration Project." Henderson, Dennis K.,and Mohktarian,Patricia L. Institute ofTransportation Studies,University of California,Davis, 1996. Vol. 1.
Analyzes thePuget Soundtelecommutingproject data todetermine trip,VMT, andemissionsreduction
Uses both case-studyand composite-averageapproaches
Implemented travel diarylogs rather than surveys
Travel mode choiceimpacts notextensively studied
Study participants notrepresentative ofgeneral workforce
Household membersnot included in study
Center versusHome-basedtelecommuting
Center-basedtelecommutingversus nottelecommuting
Total VMT versusnumber of cold starts
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Telecom-muting(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects (cont.)
"The Travel andEmissions Impacts ofTelecommuting for theState of CaliforniaTelecommuting PilotProject." Koenig, BrettE., et al. TransportationResearch, 1996. Vol 4no. 1. pp. 13-32.
Analyzes theState of Californiatelecommutingproject data todetermine trip,VMT, andemissionsreduction
Identifies the number ofand effects of non-commute trips duringdays in whichtelecommuting took place
Implemented travel diarylogs to account for alltrips taken by studypartipants
Actual vehicle modelyear and speed data isused instead of fleetaverages
Assesses the impact oflowered average speedscaused by telecommuting
Analyzes exhaust,running, and evaporativelosses
Participants were studiedbefore and aftertelecommuting began
Study participants arenot representative ofgeneral workforce andemission reductionsshould not be appliedto whole population
Does not accuratelymodel emissions fromaccelerations anddecelerations; onlyaverage speed used
Travel mode choiceimpacts notextensively studied
Household aremembers not includedin the study analysis
Does not modelindirect telecommutingimpacts (e.g.residential locationshifts)
Affect oftelecommuting onnon-commute trips
Average speeds, hotand cold starts
Total VMT versusnumber of cold starts
Variation betweenbefore and aftertelecommutinggroups
Time of day for trips
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Telecom-muting(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects (cont.)
"The Effectiveness ofTelecommuting as aTransportation ControlMeasure." Sampath,Srikanth, S. Saxene,and P. Mokhtarian. InTransportation Planningand Air Quality: Proceedings of theNational Conference,American Sociaty ofCivil Engineers, 1991.
Examines thepotential oftelecommuting asa strategy formanaging traveldemand bystudying thetravel and airqualityimplications of theState of CaliforniaTelecommutingPilot Project
Evaluates the index ofefficiency (ratio ofemissions reductions todistance reduction) fortelecommuting's successin reducing travel
Computes and comparestravel and emissionsevaluations from beforethe telecommutingproject's implementation,as well as both commuteand stay-at-home daysonce the program hadbegun
Emissions analysisincludes conversion tovehicle-based numbersfrom person-basedtelecommuting data using"vehicle movementprofiles"
Uses acceptedEMFAC7D emissionfactors
Uses existing State ofCaliforniaTelecommuting PilotProject data, thus mayhave limitedreplicability withoutsame type of datafrom othertelecommutingprojects
EMFAC7D emissionfactors are California-specific
Only addresses thedirect air qualityimpacts oftelecommuting (doesnot address indirectimpacts such as netair quality effects ofnon-transportationenergy consumedwhile telecommuting)
Travel Factors andTrip Characteristics(including: distancetraveled by auto,number of hot andcold starts, speed,type of vehicle, andambienttemperature)
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Telecom-muting(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects (cont.)
"Methodological Issuesin the Estimation of theTravel, Energy, and AirQuality Impacts ofTelecommuting." Mokhtarian, Patricia L.et al. TransportationResearch A. Vol. 29A,No. 4, 1995.
Examines existingempirical findingswith respect tothe impacts oftelecommuting ontravel, energyuse, and airquality, byaddressing eighttelecommutingpilot projects thatincludedevaluations of thetransportation-related impacts oftelecommuting
Utilizes existing datafrom telecommuting pilotprojects to draw generalconclusions on travel, airquality and energyimpacts in short and longterm
Selected pilot projectsevaluated represented amix of telecommutingproject evaluationmethodologies andvaried geographiccoverage
Presents an ideal methodfor evaluating thetransportation impacts oftelecommuting programs
Study compared pilotprojects in differentlocations (each withunique factors such asweather, transitissues, and trafficcongestion levels);therefore, conclusionsdrawn could includeerrors of comparabilityof data
Pilot projects chosendisproportionatelyrepresent westernU.S.
Only one pilot projectincluded in studyquantified emissions(used CaliforniaEMFAC7E andBURDEN7E emissionsinventory models)
Differences in dataand methodologiesfrom pilot projectsinfluences precision inevaluation of a numberof factors
Travel impacts: commute, totalweekday, andhousehold travel
Energy impacts: transportation,household and netenergy
Air quality impacts
Potential long-termimpacts
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Telecom-muting(cont.)
Macro-levelanalysis
Providesestimates ofoverall travel andemissions impactsof telecommuting
Applicable tomultiplegeographic areas
Generally unable toevaluate impacts ofsmaller-scaletelecommutingprograms
Cannot be used toevaluate impacts ofspecific programdesign elements ontelecommuting
Macro-level resultsmay have substantialuncertainty
"Energy Efficiency inthe U.S. Economy,Technical Report One: Energy, Emissions, andSocial Consequencesof Telecommuting." U.S. Department ofEnergy, DOE/PO-0026. June 1994.
Evaluates, at thenational level, thedirect and indirecteffects oftelecommuting ontravel, trafficcongestion,energy use, andemissions; alsoexamines socialimpacts.
Incorporates indirectimpacts such as latenttravel demand and urbandecentralization
Evaluates current andprojected future impacts
Uses MOBILE emissionfactors
Includes sensitivityanalysis
Uses existing algorithmssuch as the RoadwayCongestion Indexdeveloped by the TexasTransportation Institute
Study does notdistinguish betweenmarket-driventelecommuting andpotential policy-driventelecommuting (i.e.,telecommutingresulting from aspecific governmentpolicy or program
Study does not showresults for individualurban areas
Telecommutinglevels
Level of roadwaycongestion
Latent travel demand
Location patternsand urban density
Total hours of delay
Average speeds
Emissions (HC, CO,NOx)
Monetized costs andbenefits
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"TCM Analyst 1.0 andUser's Guide." Crawford, Jason A., etal. TexasTransportation Institute. For the FederalHighwayAdministration,November 1994.
Describes acomputerizedsketch planningtool, TCM Analyst1.0, includinginput datarequirements,methods of use,and an overviewof the model'sstructure andcalculationprocedures
Provides a useful andrelatively easy instructionmanual for using TCMAnalyst 1.0
Uses MOBILE5a outputdata (emission factors)as inputs to the model,providing more accurateemission benefitcalculations for eachTCM
Program only modelslimited TCMs andcannot model multipleTCM packages
Requires several runswith MOBILE5a toobtain input emissionfactors
Modeling on regional(rather thanmicroscale) basis only
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Telecom-muting(cont.)
Sketchplanning (cont.)
"Simple Methodologiesfor Quantifying VT andVMT Reductions fromTransportation Controland GrowthManagement Measuresfor Developing LocalTrip ReductionOrdinances." Evans,V. and D. Morrow. Sonoma Technology,Inc. Air & WasteManagement Assoc. 1993
Describesdevelopment ofsimplemethodologies forquantifyingreductions invehicle trips (VT)and vehicle milestraveled (VMT)from TCMs, foruse in a planning-level context;developedoriginally for theSouth Coast AirBasin
Methods to quantify VTand VMT reductions fromTCMs were based uponrelatively simple methodsfor estimating emissionsand individual TCMeffectiveness developedprior to this report for theSouth Coast AQMD
Performance-basedapproach was developedrather than usemandated transportationperformance standards
Actual experience dataused as much aspossible: estimated tripreduction levels fromeach TCM was collectedfrom other studies, andplanning-level analysisuses site-specific datainputs, thus offeringincreased precision inemissions estimates
Ranges in VT reductionsestimates address theinteractive impacts of theapplication of multipleTCMs
Equivalency factor usedto convert VMT to VT canaccount for region-specific average triplengths
Expected reductions inVT and VMT fromTCMs were estimatedbased upon a generalsurvey, so for aparticular locationdifferent assumptionsmay be needed
Applicability to otherregions outsideCalifornia limited byreport's use oftransportation dataand emissions factorsin the analysis whichwere quantified usingBURDEN and EMFACruns for 1994
Does not incorporateany consideration ofcost-effectiveness
Employeeparticipation(percentage andfrequency)
Employer-implemented home-basedtelecommutingprogram
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Telecom-muting(cont.)
Sketchplanning (cont.)
"Evaluating Travel andAir Quality Cost-Effectiveness ofTransportation DemandManagement Projects." Schreffler, Eric N.,Therese Costa, andCarl B. Moyer. InTransportationResearch Record 1520,1996.
Describes simplemethodologiesused to evaluateprojects fundedby the AB 2766vehicleregistration feeprogram inSouthernCalifornia
Methodology can beused to evaluate priorprojects or proposedfuture projects
Uses available EMFACemission rates tocalculate ROG, PM10,NOx, and CO
Study developsstandardized worksheetto evaluate projects
Study points outdrawbacks of self-reported project results
Methodology relies onparticipation dataprovided by projectproponents, whichmay not always beunbiased
EMFAC7E factors areCalifornia-specific
Trips reduced
Trip length
Prior travel mode
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Telecom-muting(cont.)
Employer TDMcost-effectivenessmodel
Estimatesreduction in andcosts of daily tripsand peak periodtrips
Aids employerdetermination ofcost-effectivenessof TDM measuresfor their particularworksite
Results may varywidely from oneemployer to the next
Many inputs may bedifficult foremployers orplanners to quantify
"TransportationDemand ManagementCost-EffectivenessModel for SuburbanEmployers." Dagang,Deborah A. JHK &Associates. InTransportationResearch Record 1404.
Reports on thedevelopment of amodel toindividuallyevaluate the cost-effectiveness of15 differentemployer-basedTDM measures insuburban settings
Focus on suburbanemployers reflectsdifferent travel-relatedcharacteristics ofsuburban and urbanareas
Spreadsheet-basedmodel is user-friendlyand readily accessible foruse at the site-specificlevel; model makessensitivity analysisrelatively simple
Eight transportationenvironments weredefined to representvarious combinations oftransportation servicecharacteristics
For employers withoutaccess to entire range ofdata necessary tooperate model, defaultvalues are included
Most employerssurveyed to developmodel were unable toprovide detailed costinformation on theTDM measures theyhad implemented
Does not calculateemissions directly
Potential for regionalbias, as model wasdeveloped in partbased on a survey ofsuburban SanFrancisco Bay Areaemployers; model alsoused the SCAQMDRegulation XV andPima Association ofGovernments TravelReduction Programemployer plandatabases
Only some TDMsincluded in modelprovide for estimatesof VT reductions
Use of default valuescould diminishesaccuracy of estimatesfor some users
Suburban employer-based TDMmeasures
Daily trips and peakperiod trips
Costs and cost-effectiveness
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Telecom-muting(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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Telecom-muting(cont.)
Comparisonand analysis ofother studies(cont.)
"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relative effective-ness of varioustransportationmeasure programs
Implementationmechanisms
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TrafficManagement
Integratedplanning/simulationmodel
Combines thestrengths ofregionaltransportationplanning modelsand trafficsimulation models
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires verydetailed input data
Requires complexcomputer model
Potentially high costto use
"IntelligentTransportation SystemsImpact AssessmentFramework: FinalReport." VolpeNational TransportationSystems Center,September 30, 1995
Describesdevelopment andapplication of ananalytical tool topredict ITSimpacts, with afocus onAdvanced TrafficManagementSystems
Model integratestransportation planningand traffic simulation inan iterative fashion, andincludes emissions andfuel consumptionmodules
Report describes use ofmodel to analyze thepotential use of ITS in theI-880 corridor in AlamedaCounty, California,modeling ramp metering,traffic signal coordination,integrated trafficmanagement, incidentmanagement, and HOVlanes
Emissions module usesaccepted EMFAC andMOBILE factors
Relatively high costand complexity
Locally specific inputdata makes the I-880results of limited use inother areas
OperationalMeasures ofEffectiveness: VMT,traffic volume,average vehiclespeed, vehicle hoursof delay, fuelconsumption
Emission Measuresof Effectiveness: CO, HC, NOx
Safety Measures ofEffectiveness: personal injurylevels, propertydamage, totalaccidents
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TrafficManagement(cont.)
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"The Effectiveness ofTransportation ControlMeasures in ReducingCongestion andImproving Air Quality." Loudon, William R., etal. JHK & Associates. Air & WasteManagementAssociation AnnualMeeting & Exhibition1993. AWMA 93-RP-149.05.
Describes adevelopedtransportationdemand modelthat integratesemissionscalculations;provides examplecalculations fromthe model
Model has a user manualthat leads the analyststep-by-step through theinput of data for regionspecific analyses
Contains extensive cost-effectiveness module
Can be used at eitherregional or a smaller areaor location
Includes exhaust andevaporative emissions
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient
Signal timingimprovements (levelnot stated)
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"Transportation ControlMeasure AnalysisProcedures." Austin,Barbara S., et al. Systems ApplicationsInternational/CaliforniaAir Resources Board.Nov 1991. SYSAPP-91/141.
Describes adevelopedtransportationdemand modeland explicitlydiscusses thecalculationmethodologyused for severaltransportationmeasures
Model quantifies keysecondary effects ofTCMs (e.g. newcarpooling programs mayattract transit ridersrather than SOV riders)
Presents all the primaryequations and variablesused to calculate theeffects of TCMs
Contains a step-by-stepprocess for evaluatingpackages of TCMs
Explains multi-attributeanalyses as applied tomultiple TCM packages
Use of the modelrequires local inputparameters to forecastlocal effectiveness;default values may notbe sufficient;participation level datais required; basecases need to matchreal conditions
Model does not coverall TCMs, but can bemodified to do so
Temporal treatment islimited to on-peak/off-peak, no spatialtreatment
Emissions calculationsare not explicitlydescribed in the samefashion as traveleffects
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TrafficManagement(cont.)
Travel demand/mode choicemodel (cont.)
"Transportation ControlMeasures for the SanFrancisco Bay Area: Analysis ofEffectiveness andCosts." Harvey, G.,and E. Deakin. ForBay Area Air QualityManagement District,October 1991.
Describes useand results of atravel demandmodel to modelVT, VMT, andemissionreductions ofvarioustransportationmeasures in theSan FranciscoBay Area
Utilized high-qualityhousehold travel surveydata and advancedmodeling capabilities
Emissions calculationsuses standardizedmethods, but takes intoaccount more subtleeffects of emissionsgeneration
Provides succinct, cleardata on results of study,including cost-effectiveness estimates
Does not providedetail on modeloperation
Many; not specified dac
Freewaythroughputmodel
May be applicableto actual corridors,given accurateknowledge of keyassumptions
Low to moderatecost
Assumptions arerequired that mayheavily impact theresults
"A Case for FreewayMainline Metering." Haboian, Kevin A. Parsons BrinckerhoffQuade & Douglas. InTransportationResearch Record 1494,1995.
Uses INTRASfreeway model tomeasure theimpact of rampmetering andfreeway(mainline)metering toimprove vehicletravel times andreduce trafficdelay
INTRAS model simulatesvehicles as separateunits rather than groups,improving simulation
Provides average vehiclespeeds on the freewayfor several scenarios andmetering configurations
Does not clearlyexplain fundamentalprinciple behindeffectiveness offreeway metering
Does not assessimpact of vehiclesdiverting aroundmetering point
Does not calculateVMT or emissionreductions
Does not discuss waysto counter politicalresistance to freewaymetering
Ramp meteringintervals
Mainline meteractivation thresholds
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Parking supplyand demandmodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires computermodel
Potentially high costto use
"Air Quality Offsets forParking." Loudon,William, et al. InTransportationResearch Record 1232,1992.
Develops anduses parkingsupply model fordowntownPortland toestimate COemissions
Uses observed price andtravel time sensitivities
Uses proven models oftravel behavior
Incorporates integratedCO emissions model
Requires parkingdatabase: number ofspaces, location, type,use patterns
Requires traveldatabase: time ofarrival, travel & workmode split
Average speed ofvehicles
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TrafficManagement(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Ramp Metering: Doesit Really Work?" Robinson, James, andMark Doctor. FHWA/ITE 1989Compendium ofTechnical Papers.
Evaluateseffectiveness ofseveral rampmetering projectsacross the nation,identifieslimitations andissues forimplementation
Compares several typesof ramp-metering projectsunder differentcircumstances
Provides effectiveness interms of vehicle speedincreases or travel timedecreases as well asreductions in accidents
Discusses types of ramp-metering systems,metering rates, rampgeometries, anddiversion problems
Some of the projectsimplemented othertransportationmeasures concurrentlywith the ramp-meteringproject, so it is difficultto examine theeffectiveness of thisprogram only
Does not quantify VMTor emissionsreductions
On-ramp queuelength
Wait times
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"EnvironmentalConsiderations forPlanning AdvancedTraffic ManagementSystems." Kraft,Walter H., and WilliamA. Redl, in ResourcePapers for the 1994ITE InternationalConference, 1994.
Reviewsenvironmentalfactors related toITS strategies,and presents acase study ofNew Jersey DOTI-80 MetropolitanArea GuidanceInformation andControl (MAGIC)project
Combines generaldiscussion with casestudy results from anactual ITS project
Evaluates changes inVMT and emissions (CO,HC, and NOx) at thecorridor level
Includes cost/benefitanalysis results
Tracks changes in VMTand emissions impactsover time
Emissions calculationmethodology andresults not presentedin great detail
Land use andphysical features
Emissions (CO, HC,NOx)
Benefit/cost ratio
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TrafficManagement(cont.)
Empiricalanalysis oftransportationmeasuredemonstrationprojects (cont.)
"ITS Benefits: Continuing Successesand Operational TestResults." Prepared byMitretek Systems forFederal HighwayAdministration. Draft,September 19, 1997.
Highlights existingand predicted ITSbenefits identifiedfrom a variety ofITS programs,including trafficmanagementprojects, focusingon U.S. DOT-funded FieldOperational Testsand otherprogramsresulting fromrecent federalinitiatives
Reports benefits from avariety of projectscovering a variety of ITStechnologies, includingseveral trafficmanagement strategies
Includes ITS and trafficmanagement benefitsrelated to safety, time,throughput, cost,customer satisfaction,energy, and environment
Includes exampleemissions results forelectronic toll collectionand traffic signal systemprojects in Oklahoma,New Jersey, LosAngeles, and Abeline(Texas)
Reports results butdoes not showanalysis methods orcalculations
Not all reported resultshave been validatedfor completeness andreliability
Varies depending onproject summarized,but can include: VMT, vehicle trips,vehicle speeds, fuelusage, emissions(HC, CO, NOx)
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"TCM Analyst 1.0 andUser's Guide." Crawford, Jason A., etal. TexasTransportation Institute. For the FederalHighwayAdministration,November 1994.
Describes acomputerizedsketch planningtool, TCM Analyst1.0, includinginput datarequirements,methods of use,and an overviewof the model'sstructure andcalculationprocedures
Provides a useful andrelatively easy instructionmanual for using TCMAnalyst 1.0
Uses MOBILE5a outputdata (emission factors)as inputs to the model,providing more accurateemission benefitcalculations for eachTCM
Program only modelslimited TCMs andcannot model multipleTCM packages
Requires several runswith MOBILE5a toobtain input emissionfactors
Modeling on regional(rather thanmicroscale) basis only
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TrafficManagement(cont.)
Sketchplanning (cont.)
"Potential Emission andAir Quality Impacts ofIntelligent Vehicle-Highway Systems." Ostria, Sergio, andMichael F. Lawrence. In TransportationResearch Record 1444,1994.
Discusses short-term and long-term impacts ofITS technologybundles, includingtraffic andincidentmanagementsystems, on trips,mode split, andemissions at aregional andcorridor level
Provides a broad initialassessment of theexpected direction ofimpact (positive,negative, insignificant,uncertain) of traffic andincident managementsystems on travelbehavior and emissions(HC, CO, NOx)
Utilizes solid a priorireasoning to predictimpacts
Discussion istheoretical rather thanempirical
Does not estimate themagnitude of travel oremissions impacts
Evaluates traffic andincident managementsystems mostly as anITS technology bundlerather than asindividual ITStechnologies orspecific trafficmanagementstrategies
Traffic flow
Vehicle trips
Trip distance
Mode shifts
Emissions (HC, CO,NOx)
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Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theimplementation ofan actualtransportationmeasure, such asreactions from thepublic and fundingsources, as wellas projectedversus actualbenefits
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from thetransportationmeasureimplementation
"Freeway RampMetering Effects inDenver." Corcoran,Lawrence J. andGordon A. Hickman. ITE 1989 Compendiumof Technical Papers.
Reviews andassesses theimplementation,systemexpansion,projected andactual benefits ofthe freeway rampmeteringdemonstrationproject begun in1981 in theDenvermetropolitan area
Compares projected andactual benefits, inpercentages, ofincreased speed,reduced VHT, reducedemissions, reducedaccidents, and minimizeddiversion
Long term nature of thedemonstration project,and subsequentexpansion of rampmetering, demonstrated aquantified level ofmotorist and mediasupport, as well as ameasure of motoristviolation rates
Does not evaluate theend resulteffectiveness in termsof VT or VMT reduced
Speed increase
Reduced VHT,emissions, andaccidents
Diversionminimization
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TrafficManagement(cont.)
Processanalysis oftransportationmeasureplanning andimplementation(cont.)
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specifictransportation measureevaluation method
Estimates VT, VMT, andemission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides a reviewof the resultsproduced bydifferent HOVfacilities in NorthAmerica, whichcould be used ifother directlyapplicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of TCM options, as wellas technology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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TrafficManagement(cont.)
Comparisonand analysis ofother studies(cont.)
"HOV Lanes and RampMetering: Can TheyWork Together for AirQuality?" Shoemaker,Bill R. and Edward C.Sullivan. TransportationResearch Board Paper940444. January 1994.
Comments on theanalysis processused to assessthe air qualityimpacts of HOVland and rampmetering projects,and examines thedegree to whichthese measuresare effective andcompatible wherejointly applied toimprove freewayoperations
Illustrates the process ofanalysis and decision-making, as well as thekey role of analyticalmodeling, required in theSan Francisco Bay Areato gain approval for HOVlane and ramp meteringprojects at the regionallevel
Examines theinterrelationships, andpotentially perverseeffects, between HOVlanes and ramp metering
Identifies need forestimatingdisaggregate mode-specific emissionfactors, includingvehicle fleetcharacteristics, andidentifies difficulties indoing so
Interrelationshipsbetween HOV lanesand ramp metering
TripReduction(cont.)
Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Implementing EffectiveTravel DemandManagementMeasures: Inventory ofMeasures andSynthesis ofExperience." COMSISCorporation. USDOT,September 1993. DOT-T-94-02.
Summarizesbroad range ofTDM measures,provides examplecase studyanalyses of each,and usescomputer modelto benchmark theeffectiveness ofeach TDM
Excellent overview of therange of TDMs possible;provides description,nature of effectiveness,application setting,effectiveness potential,and cost
Uses actual case studiesto inform the use of acomputer model forforecasting TDMeffectiveness
Provides a road-map toimplementing TDMs
Use of the modelrequires local inputparameters to forecastlocal effectiveness
Model does notincorporate anemissions calculationmodule
Most analysis is at theemployer-level ratherthan the area-level
Level of serviceprovided byemployer:information,matching services,preferential parking,ride home programs
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TripReduction(cont.)
Travel demand/mode choicemodel (cont.)
"A Survey and Analysisof EmployeeResponses toEmployer-SponsoredTrip ReductionIncentive Programs." Schreffler, Eric N., andMortero, Jose.COMSIS Corp.California AirResources Board,February 1994. Contract No. A983-187.
Describes resultsof new surveydata regardingemployee travelbehavior; usesmode choice andtravel demandmodel to predictimpacts of certainemployer-basedtransportationmeasures
Clearly explains theprocess that was used: survey data acquisition,mode choicecomputation, and TCMeffectiveness model use
Data requirements aremore readily availablethan other models
User-friendly model isavailable for outside use;users guide is alsoavailable
Survey links incentivesdirectly to impacts ontravel behavior
Model includes anawareness sub-modelthat simulates how manypeople know about thepossible transportationmeasures available tothem
Does not accuratelyaddress trip-chainingand VMT reductions(only trips)
Household conditionsare not extensivelyaccounted for
Cost-effectivenesswas not calculated
Employer-levelanalyses only, withfocus upon incentiveTCMs
Guaranteed ridehome
Company vanpools
Preferential parking
Parking fees forridesharers
Carpool subsidies &transportationallowances
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TripReduction(cont.)
Empiricalanalysis of theimpacts ofpersonalpreference andworkplaceconditions onmode choice
Somewhatapplicable tomultiple regions(but likely to beinfluenced heavilyby local factors ofthe study area)
Can be replicated(at moderate tohigh cost)
Does not requireextensivecomputer model
Uses actualsurvey data
Requires large datacollection process togenerate statisticallysignificant results
Personal preferenceand workplaceconditions difficult toimpact throughpublic policy
"The Influence ofEmployer RidesharingPrograms on EmployeeMode Choice." Ferguson, Erik. Transportation, vol 17,1990.
Analyzesaggregate-leveldata compiled bya large SouthernCalifornia regionalridesharingagency; assessesimpact ofemployercharacteristics onemployee modesplit
Analyzes a large data setcomprising almost 10%of Los Angeles areaworkforce
Utilizing existing agencydatabase is a cost-effective approach
Less accurate thandisaggregated (employeeby employee) data
Includes cost-effectiveness estimations
Some findings mayhave beencontradicted by morerecent studies (e.g.,study finds that largecorporations havebetter success withrideshare programs)
Aging data source: 1985 survey data
Los Angeles areafactors may beuncharacteristic ofother regions, soresults may not beapplicable elsewhere
Employer-derived datawas acquired usingdifferent methods
No estimates ofemissions impacts
Level of employereffort to encourageridesharing
Size of firm
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TripReduction(cont.)
Statisticalanalysis of theimpacts of landusecharacteristicsand TDMstrategies onmode choice
Identifies land useand urban designcharacteristicsthat are supportiveof walk/bike modechoice.
Standard analysisof variance usingprinciplecomponentsallowsexamination of theeffects of land useand TDMincentivestrategies onmode choiceindividually and incombination.
Resultstransferable toother urban areasin terms of relativeranking ofimportance of theland use and TDMfactors analyzed.
Precise causalityand individualimpacts of factorssuch as transitavailability or urbandensity on modechoice cannot bemeasured due tolimitations of thedatabase
Potential for need toconduct extensivefield research todetermine land usecharacteristics ateach sample worksite.
Cannot be used todetermine land useand urban designcharacteristics'impact on a specificmode choice
"The Effects of LandUse and TravelDemand ManagementStrategies onCommuting Behavior: Final Report." Prepared by CambridgeSystematics, Inc. andDeakin, Harvey,Skabardonis, Inc. forthe U.S. Department ofTransportation,November 1994.
Develops anintegrateddatabase of landusecharacteristicsand traveldemandmanagement(TDM) strategies(for a sample ofemploymentlocations) todetermine thecombined impactsof TDM programs,land use, andurban design onemployee travelbehavior.
Added land use and siteinformation from fieldobservation to the"Regulation XV" datasetof the South Coast AirQuality ManagementDistrict (which includedaggregate employeetravel characteristics andemployer incentiveprograms)
Study conducted inLos Angeles County,and thus may be lessapplicable in moredense urban areaswith factors such ashigher average densityand transit service.
Share of work tripsmade by bicycle as apercentage of the totaltrips in the data set issmall, makingidentification of worksite characteristicsthat encourageutilization of bikesdifficult.
Did not addressresidential trip end ofcommute, middaytravel, or trip chainingas factors whichinfluence mode choice
To simplify acomplicated datacollection process,somewhat arbitraryindicators were usedfor assessment of asite's urban designand land usecharacteristics.
Land use and urbandesign of worksite
TDM incentivestrategies
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TripReduction(cont.)
Empiricalanalysis ofemployer-based tripreductionprogram
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"SB 836 EvaluationMethodology: Baselineand Methodology toMeasure theEffectiveness ofVoluntary Ridesharingand Other Rule 2202ReplacementMeasures," FinalReport. Schreffler, Ericet al, for RegionalTransportationAgencies' Coalition. July 1997.
Describesmethodology forevaluation ofvoluntaryridesharing in theSouth Coast AirBasin; includesreview of currentemployer tripreduction programevaluationpractices
Methodology is rigorousand uses multiple datasources: a "State of theCommute" survey, anemployer worksiteactivity survey, and anemployee AVR survey
Methodology is designedto compare voluntaryridesharing withmandatory ridesharing,thus isolating the relativeemissions impact ofridesharing rules
Uses existing datasources where possible
Attempts to identifycausality
Methodology is designedto meet EPA requirementfor State ImplementationPlan credit
Extensive datasources are required
Obtaining analogous"before" and "after"data to comparemandatory andvoluntary ridesharingcan be difficult
Data sources andanalysis are specific toSouthern California
Primary measures: vehicle trips, VMT,emissions (CO,VOC, NOx)
Secondarymeasures: averagevehicle ridership,mode split
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TripReduction(cont.)
Empiricalanalysis ofemployer-based tripreductionprogram (cont.)
"Employee TripReduction WithoutGovernment Mandates: Cost and EffectivenessEstimates FromChicago." Pagano,Anthony and JoAnnVerdin. University ofIllinois at Chicago. TransportationResearch Board Paper971281, 1997.
Evaluated thecost andeffectiveness ofemployee tripreductionprograms throughthe use of anindependentevaluation ofdemonstrationprojectsimplemented inthe Chicago area
Estimates planning,maintenance, andvoluntary implementation,and incentive costs fortrip reduction programs
Intensive data collection,especially for costestimates, includingbefore and after surveysand interviews ofprogram administratorsparticipating in thedemonstration projects
Addresses statisticalrelationships oforganization type to costsand outcomes, of coststo strategies andincentives, of outcomesto strategies andincentives, and of cost tooutcomes
Addresses differences inoutcome byorganizational type(factory vs. office)
Made generalizedassumption of staffcosts needed toimplement tripreduction programs
Intensive datacollection requiresdemonstration projectand surveys, orapplication of Chicagoarea data
Results have limitedapplication to otherregions, as localChicago variablessuch as availability oftransit alternativesmay have influencedmodel results
Trip reductionprogramimplementationprocess utilized
Obstacles andsuccess factors
Program costs andeffectiveness
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Empiricalanalysis oftransportationmeasureimplementationprograms
Somewhatapplicable tomultiple regions
Can be replicated(at moderate cost)
Does not requireextensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
"An Employer Panel forEvaluating theEffectiveness of TripReduction Incentives." Giuliano, Genevieve,and Wachs, Martin. InPanels forTransportation Planningand Applications, ed.T.F. Golob, et al, 1997.
Discusses resultscollected onSouthernCaliforniaemployment sitessubject toSCAQMDRegulation XV,and assesses therelativeeffectiveness oftrip reductionstrategies
Utilizes the largest tripreduction measuredatabase available in theworld
Panel method allows forassessing before-and-after-TCM conditions
Database does notprovide exceptionaldetail; report does notcontain details of thelevel of incentivesupport provided toemployees
Only generalizedeffectiveness resultsare shown
TCMs were not alwaysimplemented at thetime of the survey
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TripReduction(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms(cont.)
"Reducing Drive-AloneRates at SmallEmployer Sites: Costsand Benefits of LocalTrip ReductionOrdinances: PasadenaTowers Case Study." Stewart, Jacqueline. InTransportationResearch Record 1433,1994.
Evaluates thecost effectivenessof a building-based tripreduction planimplemented incompliance to alocal ordinance inPasadena,California
Attitudinal surveyincludes the influences ofbuilding tenant companysize as well as scheduleand lifestyle ofemployees
Uses small data setstherefore results varywidely with thebehavior of a fewindividuals
Does not establish astandard to evaluateaverage vehicleridership resultsobtained
Results may not betransferable to otheremployer sites orregions
Does not quantifyemission impacts
Program cost anddistribution of cost
Benefits todeveloper, tenantsand city
Average vehicleridership
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TripReduction(cont.)
Empiricalanalysis oftransportationmeasureimplementationprograms(cont.)
"Feasibility ofEmployee TripReduction as aRegionalTransportation ControlMeasure." Lupa, MaryR. University of Illinoisat Chicago. InTransportationResearch Record 1459.
Conducts a policyanalysis ofemployee tripreduction, and apreliminary costcomparison ofemployee tripreduction amongtransportationmeasures
Evaluates effectivenessof employee tripreduction measures onimproving air qualityaccording to relief oftraffic congestion, reliefof ROG, maintenance ofpersonal privacy andautonomy, and accordingto market-based VMTpricing possibilities
Calculates themegagrams per yearreduced of the pollutantchosen to measure theeffectiveness of thetransportation measure,as well as the cost of thestrategy
Determines thatemployee trip reductionstrategies cannotsuccessfully beseparated from relatedmode split componentstrategies such as transitexpansion, transit usersubsidy, and parking fees
Does not evaluateemissions other thanROG
Cost effectiveness ofemployee tripreduction
Effectiveness ofemployee tripreduction measureson improving airquality
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Empiricalanalysis oftransportationmeasuredemonstrationprojects
Requires little orno new dataacquisition
Relatively low cost
Shows actualpotential oftransportationmeasures
Case study resultsdo not necessarilyapply to otherregions
"Evaluation of TravelDemand ManagementMeasures to RelieveCongestion." Kuzmyak, J.R., andE.N. Schreffler. Prepared by COMSISCorp. for FHWA. FHWA/SA-90/005;DOT-T-90-14. February 1990.
Performs casestudies of theeffectiveness of11 transportationdemandmanagementprograms
Shows potential forreduction in commute-based trips due toimplementation oftransportation measures
Provides high level ofdetail about the specificprograms implemented
Generally does notevaluate specific TCMindividually; programsof multiple TCMs areevaluated foreffectiveness
Does not quantifyemission reductions
Trip reductions basedupon vehicleoccupancyassumptions for eachmode choice (carpool,vanpool, transit)
Not applicable incontext of specifictransportationmeasures
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TripReduction(cont.)
Statisticalanalysis ofemployerridesharinginitiatives
Utilizes largedatabase ofexisting employersthat implementtransportationmeasures
Relatively low-cost(provided datadoes not need tobe collected)
May not assesscauses of statisticalsignificance found
Results notnecessarilyapplicable to otherregions
"Evaluation ofEmployer-SponsoredRidesharing Programsin Southern California." Ferguson, Erik T.,Georgia Institute ofTechnology. InTransportationResearch Record 1280,1990.
Analyzesdatabase ofsurveys ofemployer-sponsoredridesharingprograms inSouthernCalifornia todeterminerelevant factorson effectiveness
Utilizes large existingdatabase for the region,increasing validity ofresults
Assesses cost-effectiveness at varyingprogram sizes
Assesses interactionbetween alternative workschedules andridesharing
Attempts to explainreasons behind statisticalsignificance of certainfactors
Sample database maybe biased (they wereall clients of acentralized ridesharingagency)
Primarily analyzesemployer-basedmeasures only
Level and type ofdirect ridesharingincentives
Firm size and type
Dollars spent onrideshare programs
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Sample surveyof customertravel patternsandpreferences atshoppingcenters
Somewhatapplicable tomultiple regions(but influenced bylocal factors of thestudy area)
Does not requirean extensivecomputer model
Requires large datacollection process togenerate statisticallysignificant results
Moderate to highcost
"Analysis of IndirectSource Trip Activity:Regional ShoppingCenters." JHK &Associates/ K.T.Analytics/California AirResources Board.November 1993, ARB-R-94/510.
Surveyedcustomers ofregional shoppingcenters todeterminepotential impactof various travelreductionmeasures
Uses actual survey data(including customerdemographic and statedpreference data)
Developed calculationmethodologies specific toeach trip reductionmeasure, using site-specific data
Compares data betweenshopping centers indifferent land-use types
Assumptions arerequired to translatestated preference datato expected outcome
Does not quantifyemission reductions
Distance of travel forconsumers
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TripReduction(cont.)
Sample surveyof employer tripreductionprogram cost
Uses statisticallyrepresentativesample populationto make estimatesof overall impactof general tripreductionstrategies such asemployer-basedtrip reduction rules
Sample size (andtherefore cost)can be variedbased on level ofstatisticalaccuracy desired
Surveys can bedone periodicallyto determinechanges inprogrameffectiveness overtime
Surveys can entailsignificant costs
If surveys areperformed differentlyin different regions,direct comparisonsof results may not bevalid
Survey results canbe subject to variouskinds of responsebias
"South Coast AirQuality ManagementDistrict Regulation XVCost Survey," and"AQMD Survey Follow-Up." Ernst & Young. For South Coast AirQuality ManagementDistrict, 1992.
Estimates cost ofcomplying withSouth Coast AirQualityManagementDistrictRegulation XV tripreduction ruleusing employersurveys; follow-updocumentpresents resultsof on-siteinterviews of 17companies
Survey methodology isgeneric and can beapplied to any region
Regulation XVcompliance paperworkallowed for an exactdefinition of the "targetpopulation"
All affected companiessurveyed, not just arepresentative sample
Methodology combinesbroad survey withfocused on-siteinterviews to gaugevalidity of responses
Only quantifies cost ofridesharing programs;does not directlyquantify trip reductionsor emissionsreductions
Accuracy of employerresponses isquestionable
Study results do notallow characterizationof the linkage betweena given company'sspending on a tripreduction program withthe effectiveness ofthat program
Cost of ridesharingprogram (in $ peremployee)
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Sketchplanning
Simple tools cangenerate planning-level estimates oftransportationmeasureeffectiveness atlow cost
Generalized toolscan be somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Sketch planningresults are usuallynot the mostaccurate, dependingon the inputparameters
"Critical Analysis ofSketch-Planning Toolsfor Evaluating theEmission Benefits ofTransportation ControlMeasures." Crawford,Jason A., andRaymond A. Krammes. Prepared by TexasTransportation Institutefor FHWA, FHWA/TX-92/1279-5. December1993.
Critical analysisand sensitivityanalysis (usingdata for El Paso,Texas) of SanDiego Associationof Governments(SANDAG) TCMTools method andthe SystemsApplicationsInternational (SAI)method;summarized inTRR 1472
Provides a thoroughreview of the state of thepractice (as of 1993)
Identifies weaknesses inthe SANDAG and SAImethods as well asstrengths
Provides detailed sketch-planning analysis for ElPaso, Texas
Many of the inputs tothe SANDAG and SAImodels are difficult toquantify
The SANDAG and SAImodels do not fullyaccount for indirectimpacts and latenttravel demand
Vehicle trips
VMT
Average vehiclespeed
Emissions (HC, CO,NOx)
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TripReduction(cont.)
Sketchplanning (cont.)
"Simple Methodologiesfor Quantifying VT andVMT Reductions fromTransportation Controland GrowthManagement Measuresfor Developing LocalTrip ReductionOrdinances." Evans,V. and D. Morrow. Sonoma Technology,Inc. Air & WasteManagement Assoc.1993.
Describesdevelopment ofsimplemethodologies forquantifyingreductions invehicle trips (VT)and vehicle milestraveled (VMT)from TCMs, foruse in a planning-level context;developedoriginally for theSouth Coast AirBasin
Methods to quantify VTand VMT reductions fromTCMs were based uponrelatively simple methodsfor estimating emissionsand individual TCMeffectiveness developedprior to this report for theSouth Coast AQMD
Performance-basedapproach was developedrather than usemandated transportationperformance standards
Actual experience dataused as much aspossible: estimated tripreduction levels fromeach TCM was collectedfrom other studies, andplanning-level analysisuses site-specific datainputs, thus offeringincreased precision inemissions estimates
Ranges in VT reductionsestimates address theinteractive impacts of theapplication of multipletransportation measures
Equivalency factor usedto convert VMT to VT canaccount for region-specific average triplengths
Expected reductions inVT and VMT fromTCMs were estimatedbased upon a generalsurvey, so for aparticular locationdifferent assumptionsmay be needed
Applicability to otherregions outsideCalifornia limited byreport's use oftransportation dataand emissions factorsin the analysis whichwere quantified usingBURDEN and EMFACruns for 1994
Does not incorporateany consideration ofcost-effectiveness
Employeeparticipation(percentage andfrequency)
Trip length
Bike parking facilities
Existence/extent ofbike path system
Existence of showerfacilities
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TripReduction(cont.)
Employer TDMcost-effectivenessmodel
Estimatesreduction in andcosts of daily tripsand peak periodtrips
Aids employerdetermination ofcost-effectivenessof TDM measuresfor their particularworksite
Results may varywidely from oneemployer to the next
Many inputs may bedifficult foremployers orplanners to quantify
"TransportationDemand ManagementCost-EffectivenessModel for SuburbanEmployers." Dagang,Deborah A. JHK &Associates. InTransportationResearch Record 1404.
Reports on thedevelopment of amodel toindividuallyevaluate the cost-effectiveness of15 differentemployer-basedTDM measures insuburban settings
Focus on suburbanemployers reflectsdifferent travel-relatedcharacteristics ofsuburban and urbanareas
Spreadsheet-basedmodel is user-friendlyand readily accessible foruse at the site-specificlevel; model makessensitivity analysisrelatively simple
Eight transportationenvironments weredefined to representvarious combinations oftransportation servicecharacteristics
For employers withoutaccess to entire range ofdata necessary tooperate model, defaultvalues are included
Most employerssurveyed to developmodel were unable toprovide detailed costinformation on theTDM measures theyhad implemented
Does not calculateemissions directly
Potential for regionalbias, as model wasdeveloped in partbased on a survey ofsuburban SanFrancisco Bay Areaemployers; model alsoused the SCAQMDRegulation XV andPima Association ofGovernments TravelReduction Programemployer plandatabases
Only some TDMsincluded in modelprovide for estimatesof VT reductions
Use of default valuescould diminishesaccuracy of estimatesfor some users
Suburban employer-based TDMmeasures
Daily trips and peakperiod trips
Costs and cost-effectiveness
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TripReduction(cont.)
Case studyanalysis
Analyzing casestudies oftransportationprojects isrelatively easy andinexpensive
Different casestudies can becompared todetermine factorsinfluencing theeffectiveness ofan transportationmeasure
Case-study analysisfrequently does notprovide rigorousquantitative results
Effectiveness ofcase studies may bedue to local factorsspecific to that case
"TransportationDemand Management: Case Studies ofMedium-SizedEmployers." Rutherford, G. Scott etal. In TransportationResearch Record 1459.
Presents travelmode split resultsfor 14 medium-sized employersthat practicevarious forms oftransportationdemandmanagement
Chosen companiesrepresent a variety oflocations, business type,and transportationmeasures.
Explains regionalvariation of policy andconstraints fortransportation measures(parking availability,price, publictransportation network)
Data collected do notcontribute to a clearconclusion on themost effectivetransportationmeasure
Does not providediscussion of emissionbenefits
Does not containcost/benefit analysis
Transportation modesplit: singleoccupant vehicle,transit, carpool
Employeetransportationcoordination supporttime
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Policy analysisof transpor-tationmeasures
Addressespolitical feasibilityof transportationmeasureimplementationand generalizedestimate ofsuccess givenlocal travelbehavior andcharacteristics.
Relatively simpleand inexpensiveto conduct, as itrequires noprimary research
Unlikely to provideprecise emissionestimates
"Feasibility ofEmployee TripReduction as aRegionalTransportation ControlMeasure." Lupa, MaryR. University of Illinoisat Chicago. InTransportationResearch Record 1459.
Conducts a policyanalysis ofemployee tripreduction, and apreliminary costcomparison ofemployee tripreduction amongtransportationmeasures
Analyzes shortcomingsto indirect transportationmeasures such asemployee trip reduction
Provides a solid overviewof employee tripreduction as an evolvingTCM and an arena forstrategic planning usingtools such as directpolitical action, classiceconomics, technologicalimplementation, pricing,and regional consensusbuilding
Draws conclusions asto feasibility ofimplementingemployee tripreduction, but gives noprecise estimation ofemissions
Employee tripreduction
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TripReduction(cont.)
Processanalysis oftransportationmeasureplanning andimplementation
Explains lessonslearned during theplanning andimplementation ofan actualtransportationmeasure, such asreactions toexpect from thepublic and fundingsources
Provides pros andcons of planningandimplementationmethods
Does not necessarilyhelp quantify VT,VMT, or emissionsreductions from theTCM implementation
Cost can vary greatly
"Transportation ControlMeasures Analyzed forthe WashingtonRegion's 15 PercentRate of Progress Plan." FHWA/MetropolitanWashington Council ofGovernments, February1995.
Providescomprehensiveevaluation of theselection andquantificationprocessperformed by theMWCOG forassessing varioustransportationmeasures
Addresses the strengthsand weaknesses of thebottom-up, multiplecommittee planningprocess used by theCOG
Provides extensive, cleardetail (and strengths andweaknesses) of both theevaluation tools used andeach specific TCMevaluation method
Estimates VT, VMT, &emission reductions andcost-effectiveness
Requires an extensivestudy of already-performed process
None (factorsanalyzed areapplicable to eachtransportationmeasure analyzedduring the process)
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Comparisonand analysis ofother studies
Relativelyinexpensive andsimple to conduct,because itrequires noprimary research
Provides anintroduction to therange of resultsproduced bydifferent studies,which could beused if otherdirectly applicableresearch is notavailable
Identifiesadvantages anddisadvantages ofseveralmethodologies
Results are notdirectly applicable toother regions (theydo not incorporatecharacteristics ofother regions)
Unlikely to provideprecise estimates
"An Assessment ofTransportation ControlMeasures,TransportationTechnologies, andPricing/RegulatoryPolicies." Euritt, MarkA., et al. University ofTexas, Austin, Centerfor TransportationResearch/TellusInstitute. CTR SEDC-1, June 1995.
Assesses severalstudies thatanalyze a host oftransportationmeasures,technologyoptions, andpolicies for totaleffectiveness andcosts/benefits
Provides a solid overviewof the range (and effects)of transportation measureoptions, as well astechnology and policyoptions
Focuses upon energyefficiency impacts inaddition to emissions andVMT
Report does notcontain a methodologyfor evaluating newTCM plans, but follow-on report focusesupon these strategies
Estimates may be toorough to apply to otherprograms in otherregions
Impacts: vehicletrips, vehicle milestraveled, andemissions
Costs
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"Assessment of TravelDemand ManagementApproaches atSuburban ActivityCenters." Bhatt, Kiran,and Higgins, Thomas. K.T. Analystics. U.S.DOT, July 1989.
Surveys researchstudies andinterviews TCMprogramcoordinators toprovide anoverview of therange ofeffectiveness ofemployer-basedTCM programs
Provides a large numberof case study examplesof both effective andineffective TCMprograms
Makes recommendationsto employers on how todevelop a TCM program
Provides a good checklistof topics to address whendeveloping a TCMprogram
Report does notcontain a methodologyfor forecasting theeffectiveness of newTCM plans
Only generalizedevaluation of TCMeffectiveness
Relativeeffectiveness ofvarioustransportationmeasure programs
Implementationmechanisms
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TripReduction(cont.)
Comparisonand analysis ofother studies(cont.)
"ManagingTransportationDemand: MarketsVersus Mandates." Giuliano, Genevieve,and Martin Wachs. Reason Foundation. Policy Insight No. 142,September 1992.
Comparescongestion pricingwith RegulationXV for theSouthernCalifornia area;describes prosand cons of eachmeasure anddiscussesimplications
Provides typology oftransportation measuresand identifieseffectiveness andcommon barriers toimplementation
Simple side-by-sidecomparison of VMTreduction and cost-effectiveness for eachtransportation measure
Makes policyrecommendations toimprove eachtransportation measure
Provides little detailabout logistics ofimplementing thepolicyrecommendations
Does not quantifyemission reductions
Direct vs. indirectimplementation
Market-based vs.performance-basedimplementation
Efficiency and equityconsiderations
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"The Equity and CostEffectiveness ofEmployee CommuteOptions Programs." Farkas, Z. Andrew. Morgan StateUniversity. TRB960078, January 1996.
Analyzes theresults of surveysand transportationmeasuremodeling studiesperformed for theBaltimore andPhiladelphiaregions
Shows different methodsof using the same model: Travel DemandEvaluation Modeldeveloped by COMSIS
Provides a discussion ofsocial equityconsiderations based ona survey of the tworegions
Philadelphia modelingassumed averagevehicle ridershiptargets were reachedand results are onlyapplicable relative toeach scenario
Baltimore modeling didnot estimate emissionsreductions
Rideshare promotionlevel
Parking charge level
Transit subsidylevels
Work scheduleflexibility
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"Evaluation ofEmployee TripReduction ProgramsBased on California'sExperience withRegulation XV." Orski,C. Kenneth. Institute ofTransportationEngineers. January1994.
Summarizes theresults of anevaluation ofemployee tripreductionprograms, basedon California'sexperience withRegulation XV
As their techniques andtargets are closelyparallel, empirical datafor Regulation XV wasused to representprojected results of theFederal Clean Air Act, solessons evaluated maybe relevant to othermetropolitan areas
Able to draw generalconclusions of employeetrip reduction programeffectiveness, based onassessment of numerousCalifornia studiesavailable at the time
Report does notcontain a methodologyfor evaluating newTCM plans
California-specificfactors may influenceand limit applicabilityof conclusions to otherregions
South Coast AirQuality ManagementDistrict RegulationXV results to date
Areawide programimpact
Program costs andeffectiveness
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TripReduction(cont.)
Comparisonand analysis ofother studies(cont.)
"Employee TripReduction Programs: An Evaluation." Orski,C. Kenneth. InTransportationQuarterly, Vol. 47, No.3, July 1993.
Addressesfeasibility andcost of attainingthe mode shiftgoal in CAA182(d)(1)(B), andthe resultingimpact onregional tripvolume, vehiclemiles traveled,automotiveemissions, and airquality if the goalswere met
As their techniques andtargets are closelyparallel, empirical datafor Regulation XV wasused to representprojected results of theFederal Clean Air Act, solessons evaluated maybe relevant to othermetropolitan areas
Able to draw generalconclusions of employeetrip reduction programeffectiveness, based onassessment of numerousCalifornia studiesavailable at the time
California-specificfactors may influenceand limit applicabilityof conclusions to otherregions
Report does notcontain a methodologyfor evaluating newTCM plans
South Coast AirQuality ManagementDistrict RegulationXV results to date
Long-term programeffects on modalchoice
Areawide programimpact
Program costs andeffectiveness
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VMT Fees Travel demand/mode choicemodel
Somewhatapplicable tomultiple regions
Analyst can varyinput parameters
Requires region-specific householdsurvey, land use,socioeconomic, andtravel cost data
Requires complexcomputer model
Potentially high costto use
"Transportation PricingStrategies forCalifornia: AnAssessment ofCongestion, Emissions,Energy and EquityImpacts." California AirResources Board, June1995. Report No. 92-316.
Develops anduses acomprehensivetravel demandmodel to estimatethe impacts ofmultipletransportationmeasures
Uses actual, availableprice elasticities
Establishes base case bycomparing to actualtravel data
Explores interrelationsbetween pricingstrategies
Does not contain ahighway-networkmodel to include level-of-service changes
Forecasts rely onestimations ofchanges in householdtravel data
Fee level
Price elasticity
Interrelationshipsbetween pricingstrategies
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