Status of the Roadside Design Guide Update

AASHTO Subcommittee on Design July 19-23 2009

Indianapolis, Indiana

Keith A. Cota, New Hampshire Department of Transportation

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Roadside Design Guide

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• Update Objectives

• Research Studies

• Schedule for Completion

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Presentation Overview

Statistics Updated

Incorporated Latest Research

Resolved Conflicts related to Clear Zone (NCHRP 20-7, Task 171) within AASHTO Documents

• Clear zone• Clear recovery area• Horizontal clearance• Lateral offset

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Update Objectives

Minimum Lateral Offset

vs.

Clear Zone

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Update Objectives

Reduced listing of hardware by referencing AASHTO-AGC-ARTBA Task Force 13 Report, “A Guide To Standardized Highway Barrier Hardware”

http://aashtotf13.org

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Update Objectives

Referenced Acceptance Letters from FHWA’s Office of Safety

http://safety.fhwa.dot.gov/roadway_dept/road_hardware/index.htm

Added Reference for Updated Crash Test Criteria Under MASH and FHWA/AASHTO Implementation Plan

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Update Objectives

New chapter on Low Volume Roads, including guidance on: Clear zone Drainage placement Slope and ditch cross-sections Barriers (TL-2) Sign supports Utility pole placement etc. 8

Update Objectives

Updated chapter for Urban Areas, including guidance on: clear zone lateral offset (4-6 ft) landscaping (including median applications) sidewalk placement slope and ditch cross-sections sign supports utility poles placement traffic signals mailbox locations etc. 9

Update Objectives

Urban rights-of-way are often extremely restricted, limiting the applicability of clear-zone practice – even in suburban-to-urban transitions.

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Urban Chapter Objectives

Urban Chapter Landscape Buffer (Planting Strip) Configuration

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• RSAP (Roadside Safety Analysis Program)– Update will maintain current RSAP

program – Intent to supplement at time of completion

of NCHRP 22-27, “RSAP Update,” currently under contract

– Anticipated completion – 2010 or sooner?

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Update Objectives

• Technical Assistance through NCHRP 20-7, Task 240, “Update of AASHTO Roadside Design Guide”– Contract with King Mak– Provide technical assistance, research

overview, and chapter consistency review

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Update Objectives

• NCHRP Project 22-17 – “Recommended Guidelines for Curbs and Curb-Barrier Combinations”

• NCHRP 22-19 “Aesthetic Concrete Barrier and Bridge Rail Designs”

• NCHRP 16-04 “Design Guidelines for Safe and Aesthetic Roadside Treatments in Urban Areas”

• NCHRP 22-18 “Crashworthy Work Zone Traffic Control Devices”

• NCHRP 20-7 (196) “Development of a Guide to Crashworthy Bridge Rail Systems”

• NCHRP 16-04 “Median Intersection Design for Rural High-Speed Divided Highways”

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Research Studies

• NCHRP 17-13 “Strategic Plan for Improving Roadside Safety”

• NCHRP 20-7 (171) “Guidelines for the Selection of Cable Barrier Systems”

• FHWA Memoranda on:– “Guidelines for the Selection of W-Beam Barrier Terminal”

– “High Tension Cable on Slopes”

– “Design Considerations for Large Trucks”

• Midwest Pooled-Fund States Study “Development of Guardrail Treatments at Intersecting Roadways”

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Research Studies

• Schedule for Adoption– Final chapter reviews and Technical

Committee balloting at September 2009 meeting in Delaware

– Ballot to SCOD in Fall 2009– TCRS to address SCOD ballot

comments, Sept 2010 (or sooner)– Ballot to SCOH in Fall 2010 (or sooner)

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Schedule

AASHTO Subcommittee on DesignAASHTO Subcommittee on DesignIndianapolis, Indiana Indianapolis, Indiana

July 19-23, 2009July 19-23, 2009

AASHTO Manual for AASHTO Manual for Assessing Safety Hardware Assessing Safety Hardware

(MASH)(MASH)

Technical Committee on Roadside SafetyTechnical Committee on Roadside Safety

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BackgroundBackground

1962: HRCS Circular 482 – one-page document, specified 1962: HRCS Circular 482 – one-page document, specified vehicle mass, impact speed, and approach vehicle mass, impact speed, and approach angle for angle for crash testscrash tests

1973: NCHRP Report 153 – 16-page document, based on 1973: NCHRP Report 153 – 16-page document, based on technical input from 70+ individuals and technical input from 70+ individuals and

agencies agencies and a special ad-hoc paneland a special ad-hoc panel1978: TR Circular 191 – addressed minor issues 1978: TR Circular 191 – addressed minor issues 1980: NCHRP Report 230 – 36-page document, brought 1980: NCHRP Report 230 – 36-page document, brought

procedures up to date with available procedures up to date with available technology and technology and practices, updated the evaluation practices, updated the evaluation criteriacriteria

1993: NCHRP Report 350 – Comprehensive update of 2301993: NCHRP Report 350 – Comprehensive update of 2302009: Manual for Assessing Safety Hardware (MASH)2009: Manual for Assessing Safety Hardware (MASH) 1818

MASH Summary of ChangesMASH Summary of Changes

Test matrices and conditionsTest matrices and conditions Test installationTest installation Test vehicle specificationsTest vehicle specifications Evaluation criteriaEvaluation criteria Test documentationTest documentation In-service performance evaluationIn-service performance evaluation

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Small car impact angle Small car impact angle (20 degree to 25 degree)(20 degree to 25 degree).. Impact speed for single unit truck test Impact speed for single unit truck test (80 (80

km/h [50 mph] to 90 km/h [56 mph]).km/h [50 mph] to 90 km/h [56 mph]).

Impact angle for terminals and crash Impact angle for terminals and crash cushions cushions (20 degree to 25 degrees).(20 degree to 25 degrees).

Gating terminal/crash cushion Gating terminal/crash cushion (Reduce angle (Reduce angle from 15 degrees to 5 degrees).from 15 degrees to 5 degrees).

Mid-size car test Mid-size car test (Add 1500A test vehicle for (Add 1500A test vehicle for staged impact attenuation devices).staged impact attenuation devices).

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Test Matrices and ConditionsTest Matrices and Conditions

Test Matrices and ConditionsTest Matrices and Conditions

Barrier Testing Heights Barrier Testing Heights (Establish max. for (Establish max. for small vehicle and min. height for pickup test)small vehicle and min. height for pickup test)

Critical Impact Points (CIPs) for reverse Critical Impact Points (CIPs) for reverse direction impactsdirection impacts

TMA optional tests to mandatory TMA optional tests to mandatory (Define (Define max/min truck weight, control ballast shifting and vehicle max/min truck weight, control ballast shifting and vehicle braking)braking)

Variable message sign and arrow board Variable message sign and arrow board trailers trailers (Require same test criteria as TMAs)(Require same test criteria as TMAs)

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Support structures and work zone traffic Support structures and work zone traffic control devices control devices (Add light truck test in addition to (Add light truck test in addition to the small vehicle testing criteria)the small vehicle testing criteria)

Longitudinal channelizing barricades Longitudinal channelizing barricades (Add new category and recommended test matrix)(Add new category and recommended test matrix)

EDR data collection EDR data collection (Provide data on impact (Provide data on impact conditions and accelerations from vehicle)conditions and accelerations from vehicle)

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Test Matrices and ConditionsTest Matrices and Conditions

Test Installation Test Installation

Soil Condition Soil Condition (soil type, gradation, compaction and (soil type, gradation, compaction and density)density)

Embedment of Posts Embedment of Posts (not necessary with (not necessary with reporting of soil conditions)reporting of soil conditions)

Components Components (provide documentation of components (provide documentation of components used)used)

Installation Lengths Installation Lengths (document length of test (document length of test installation)installation)

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Test VehiclesTest Vehicles Test vehicles Test vehicles (change small vehicle and pickup)(change small vehicle and pickup)

Single unit truck mass Single unit truck mass (from 18000 # to 22000 #)(from 18000 # to 22000 #)

Light truck test vehicle Light truck test vehicle (Min. c.g. height of 28 inches)(Min. c.g. height of 28 inches) Vehicle age Vehicle age (six years older or less)(six years older or less)

Truck box attachment Truck box attachment (limit detachment, reduce (limit detachment, reduce inconclusive testing results)inconclusive testing results)

Vehicle damage Vehicle damage (document external vehicle crush (document external vehicle crush damage using NASS procedures)damage using NASS procedures)

Crushable nose characteristics Crushable nose characteristics (develop updated (develop updated surrogate vehicle testing from 1981 Volkswagen Rabbit)surrogate vehicle testing from 1981 Volkswagen Rabbit)

TMA support vehicle TMA support vehicle (Report maximum weight of (Report maximum weight of support vehicle) support vehicle)

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Evaluation CriteriaEvaluation Criteria Occupant risk (Modify calculations for Occupancy Occupant risk (Modify calculations for Occupancy

Impact Velocity and Ridedown Acceleration with vehicle Impact Velocity and Ridedown Acceleration with vehicle yawing)yawing)

Windshield damage (Provides more quantitative criteria; Windshield damage (Provides more quantitative criteria; apply criteria to structural support devices the same for apply criteria to structural support devices the same for work zone devices)work zone devices)

Occupant compartment damage (Set objective criteria)Occupant compartment damage (Set objective criteria) Marginal pass (Strictly pass or fail criteria results)Marginal pass (Strictly pass or fail criteria results) Maximum roll angle (Roll and pitch angle at 75 degrees)Maximum roll angle (Roll and pitch angle at 75 degrees) Exit conditions (Report lane intrusions and exit angle Exit conditions (Report lane intrusions and exit angle

with exit box criteria)with exit box criteria) Vehicle rebound for crash cushions (reporting criteria)Vehicle rebound for crash cushions (reporting criteria)

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In-Service EvaluationIn-Service Evaluation

Encourage in-service evaluation to demonstrate Encourage in-service evaluation to demonstrate satisfactory field performance.satisfactory field performance.

Pool resources (partnering) between State Pool resources (partnering) between State proprietary device manufacturers.proprietary device manufacturers.

Disseminate information through resource Disseminate information through resource channels like National Technical Information channels like National Technical Information Services (NTIS), FHWA regional resource centers, Services (NTIS), FHWA regional resource centers, and State pooled fund consortiums.and State pooled fund consortiums.

Consider the establishment of new national center Consider the establishment of new national center on in-service evaluation. on in-service evaluation.

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Full Scale Crash TestsFull Scale Crash TestsUnder NCHRP 22-14(02) Under NCHRP 22-14(02)

Conducted several full-scale crash tests of Conducted several full-scale crash tests of existing hardware, including:existing hardware, including:– Strong Post W-Beam System Strong Post W-Beam System – Midwest Guardrail SystemMidwest Guardrail System– New Jersey Shaped Concrete BarrierNew Jersey Shaped Concrete Barrier– F-Shape temp. concrete barrier with 3-loop connectionF-Shape temp. concrete barrier with 3-loop connection– Iowa TransitionIowa Transition– Tangent Guardrail terminalTangent Guardrail terminal– New Jersey Shaped Concrete Barrier (32 inches), New Jersey Shaped Concrete Barrier (32 inches),

failed TL-4 under MASHfailed TL-4 under MASH

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All highway safety hardware All highway safety hardware accepted using criteria contained in accepted using criteria contained in NCHRP 350 may remain in place and NCHRP 350 may remain in place and may continue to be manufactured may continue to be manufactured and installed.and installed.

Highway safety hardware accepted Highway safety hardware accepted using NCHRP Report 350 criteria is using NCHRP Report 350 criteria is not required to be retested or not required to be retested or recertified using MASH criteria.recertified using MASH criteria.

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AASHTO/FHWA Joint AASHTO/FHWA Joint Implementation PlanImplementation Plan

If highway safety hardware that has been If highway safety hardware that has been accepted by FHWA using criteria accepted by FHWA using criteria contained in NCHRP Report 350 fails contained in NCHRP Report 350 fails testing using MASH criteria, AASHTO and testing using MASH criteria, AASHTO and FHWA will jointly review the test results FHWA will jointly review the test results and determine a course of action.and determine a course of action.

Upon adoption of MASH by AASHTO, any Upon adoption of MASH by AASHTO, any new highway safety hardware not new highway safety hardware not previously evaluated shall utilize MASH previously evaluated shall utilize MASH for evaluation and testing.for evaluation and testing.

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MASH ImplementationMASH Implementation

Any new or revised highway safety Any new or revised highway safety hardware under development at the time hardware under development at the time the MASH is adopted may continue to be the MASH is adopted may continue to be tested using the criteria in NCHRP 350. tested using the criteria in NCHRP 350.

However, FHWA will not issue However, FHWA will not issue acceptance letters for new or revised acceptance letters for new or revised highway safety hardware tested using highway safety hardware tested using NCHRP Report 350 criteria after January NCHRP Report 350 criteria after January 1, 2011. 1, 2011.

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MASH ImplementationMASH Implementation

Agencies are Agencies are encouragedencouraged to upgrade to upgrade existing highway safety hardware existing highway safety hardware that has not been accepted under that has not been accepted under NCHRP Report 350 or MASH:NCHRP Report 350 or MASH:– during reconstruction projects, during reconstruction projects, – during 3R projects, orduring 3R projects, or– when the system is damaged beyond when the system is damaged beyond

repair.repair.

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MASH ImplementationMASH Implementation

MASH ImplementationMASH Implementation

Highway safety hardware not Highway safety hardware not accepted under NCHRP Report 350 or accepted under NCHRP Report 350 or MASH with no suitable alternatives MASH with no suitable alternatives available may remain in place and available may remain in place and may continue to be installed. may continue to be installed.

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Contact InformationContact Information

Keith A. Cota, ChairmanKeith A. Cota, ChairmanAASHTO Technical Committee on Roadside AASHTO Technical Committee on Roadside

Safety Safety New Hampshire DOTNew Hampshire DOTHazen Drive, PO Box 483 Hazen Drive, PO Box 483 Concord, NH 03302-0483Concord, NH 03302-0483Tel: 603-271-1615Tel: 603-271-1615Email: Email: kcota@dot.state.nh.uskcota@dot.state.nh.us

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