Technical Content Changes in the 2010 Highway Capacity Manual

Richard Dowling Dowling Associates

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Presentation Outline

Technical InnovationsUninterrupted flow facilities (freeways, rural highways)Interrupted flow facilities (urban streets, signals)

Active Traffic Management

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Technical Innovations New speed-flow equations New freeway analysis software New weaving method Service volume tables

Uninterrupted Flow Facilities3

Speed-Flow Curves4

Free-Flow SpeedNo longer function of number of lanesRamp density substituted for interchange density

New curve for 75 mph free-flow speed

Speed does not drop until 1200 vph/ln reached

5 Source: Draft HCM 2010 Materials, Kittelson & Associates

Weaving Sections6

Changes to Current MethodNew weaving section typesNew method for estimating speedWeaving length dependent on demands.New method for estimating capacity

Freeway Facility Analysis7

Modifications to reflect changes in other chapters

New software implementation (FREEVAL)

Updated capacity information for:Work ZonesWeather (rain, snow, wind, visibility)Incidents

Analysis Over Time & Space8

D/C SS1 SS2 SS3 SS4 SS5 SS616:00 0.68 0.75 0.72 0.72 0.80 0.7316:30 0.75 0.85 0.82 0.82 0.93 0.8217:00 0.87 0.97 0.90 0.90 1.03 0.9317:30 0.82 0.90 0.85 0.85 0.98 0.8518:00 0.73 0.78 0.73 0.73 0.80 0.7018:30 0.58 0.62 0.58 0.58 0.62 0.60MPH16:00 63 62 63 63 61 6216:30 62 60 61 61 58 6117:00 60 57 59 29 41 5817:30 61 59 19 15 35 6018:00 62 62 62 27 48 6318:30 64 64 64 64 64 64

FREEVAL Outputs (Speed)9

1

3

50.00

10.00

20.00

30.00

40.00

50.00

60.00

1 2 3 4 5 6 7 8 9 10 11

TimeInterval

Spee

d(m

i/hr)

SegmentNumber

Service Volume Tables10

Multi-lane Highways

Bicycle LOS analysis added

Service volume tables

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Two Lane Highways

Two-way analysis methodology dropped.

Some revisions to curves and tables.

New road class added for built-up areas.LOS based on % free-flow speed

Bicycle LOS on two-lane highways.

Service volume tables

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Technical Innovations: New methods for arterials and signals New method for signals in an interchange New method for roundabouts New method for multimodal level of service

Interrupted Flow Facilities13

Multimodal Level of Service

Simultaneous analysis of LOS for auto, bus, bike, ped.

A method for allocating scarse street right-of-wayto the various modal users of the street.

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Sharing the Street15

Mode Before After

Auto C D

Bus B C

Bicycle F D

Pedestrian E E

Before

After

Urban Street Analysis

Predict Stops, Speed, Queues

Models signal coordination force offs, yields

Mixed street: signal, stops, roundabout

Sensitive to access management driveways, median breaks

Service Volume Table

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Urban Street Service Vol. Table17

Signalized Intersection Updates

Incremental queue analysis (IQA)

Traffic actuated signalsMin. green, passage time, recall, dual entry, Dallas phasing, simultaneous gap out, detector length.

Left turn queue overflow check

Volume/capacity ratio check

Level of service for bicycles and pedestrians

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Incremental Queue Analysis19

Que

ued

Vehi

cles

Time

Delay polygon for shared left-through lane with permitted lefts

Q1

Q2

Q3

D1 D2 D3 D4

Left Turn Overflow Check20

If left turn overflow occurs, review results

Volume/Capacity Ratio Check

if: v/c > 1.00

Then the signalized intersection LOS is F

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Two-Way Stop Updates

Extended to 6-lane arterials.

U-turns

Analysis of shared lanes, short lanes

Pedestrian crossings analysis

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All Way Stop Updates

Queuing model added

Explicit guidance for 6-lane streets

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Roundabouts Update

New methodologyLee Rodegerdts

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Interchange Ramp Terminals

Methodology for choosing interchange types

Lost capacity due to:Queue spillbacksUneven lane utilizationDemand starvation

Performance MeasuresLOS based on OD DelayV/C and queue storage ratio

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New chapter on the continuous real time monitoring and management of both demand and capacity

Active Traffic Management26

Demand Metering27

FHWA Ramp Management and Control Primer

Congestion Pricing28

FHWA, MinnDOT Technologies that Complement Congestion Pricing PrimerCongestion Pricing Primer

Traveler Information Systems29

Metropolitan Transportation Commission, Copyright 2009 http://traffic.511.org

http://traffic.511.org/

Managed Lanes and Shoulders 30

Google Street View

FHWA Managed Lanes Primer

HOV Lanes Peak Shoulder Use

Adaptive Signal Control31

Source: Doug GettmanSiemens, FHWAACS-Lite

Speed Harmonization32

Source: Jessie Yung, FHWA

Incident Management33

Source: FHWA, Regional Traffic Incident Management Programs

Work Zone Management34

Source: FHWA, Benefits of Using Intelligent Transportation Systems in Work Zones

Active Traffic Management

Chapter is first stage place holder.

Provides basic information on active traffic management measures

Provides references from the literature

Describes applicability of HCM or microsimulation methods to evaluation

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Conclusion The New HCM

New methods for freeways and streets

Service volume tables for planning apps

New material to aid software programmers

Guidance on the use of microsimulation

Information on Active Traffic Management

New tools for multimodal planning

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Questions/Comments

Richard DowlingDowling Associates, Oakland, CA510-839-1742 ext 120rdowling@dowlinginc.com

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Technical Content Changes in the 2010 Highway Capacity ManualPresentation OutlineUninterrupted Flow FacilitiesSpeed-Flow CurvesSlide Number 5Weaving SectionsFreeway Facility AnalysisAnalysis Over Time & SpaceFREEVAL Outputs (Speed)Service Volume TablesMulti-lane HighwaysTwo Lane HighwaysInterrupted Flow FacilitiesMultimodal Level of ServiceSharing the StreetUrban Street AnalysisUrban Street Service Vol. TableSignalized Intersection UpdatesIncremental Queue AnalysisLeft Turn Overflow CheckVolume/Capacity Ratio CheckTwo-Way Stop UpdatesAll Way Stop UpdatesRoundabouts UpdateInterchange Ramp TerminalsActive Traffic ManagementDemand MeteringCongestion PricingTraveler Information SystemsManaged Lanes and Shoulders Adaptive Signal ControlSpeed HarmonizationIncident ManagementWork Zone ManagementActive Traffic ManagementConclusion The New HCMQuestions/Comments