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Status of the Roadside Design Guide Update AASHTO Subcommittee on Design July 19-23 2009 Indianapolis, Indiana Keith A. Cota, New Hampshire Department.

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Presentation on theme: "Status of the Roadside Design Guide Update AASHTO Subcommittee on Design July 19-23 2009 Indianapolis, Indiana Keith A. Cota, New Hampshire Department."— Presentation transcript:

1 Status of the Roadside Design Guide Update AASHTO Subcommittee on Design July Indianapolis, Indiana Keith A. Cota, New Hampshire Department of Transportation 1

2 Roadside Design Guide 2

3 Update Objectives Research Studies Schedule for Completion 3 Presentation Overview

4  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 4 Update Objectives

5 Minimum Lateral Offset vs. Clear Zone 5 Update Objectives

6  Reduced listing of hardware by referencing AASHTO-AGC-ARTBA Task Force 13 Report, “A Guide To Standardized Highway Barrier Hardware”  6 Update Objectives

7  Referenced Acceptance Letters from FHWA’s Office of Safety road_hardware/index.htm  Added Reference for Updated Crash Test Criteria Under MASH and FHWA/AASHTO Implementation Plan 7 Update Objectives

8  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

9  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

10 Urban rights-of-way are often extremely restricted, limiting the applicability of clear-zone practice – even in suburban-to-urban transitions. 10 Urban Chapter Objectives

11 Urban Chapter Landscape Buffer (Planting Strip) Configuration 11

12 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? 12 Update Objectives

13 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 13 Update Objectives

14 NCHRP Project – “Recommended Guidelines for Curbs and Curb-Barrier Combinations” NCHRP “Aesthetic Concrete Barrier and Bridge Rail Designs” NCHRP “Design Guidelines for Safe and Aesthetic Roadside Treatments in Urban Areas” NCHRP “Crashworthy Work Zone Traffic Control Devices” NCHRP 20-7 (196) “Development of a Guide to Crashworthy Bridge Rail Systems” NCHRP “Median Intersection Design for Rural High-Speed Divided Highways” 14 Research Studies

15 NCHRP “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” 15 Research Studies

16 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) 16 Schedule

17 AASHTO Subcommittee on Design Indianapolis, Indiana July 19-23, 2009 AASHTO Manual for Assessing Safety Hardware (MASH) Technical Committee on Roadside Safety 17

18 Background 1962: HRCS Circular 482 – one-page document, specified vehicle mass, impact speed, and approach angle for crash tests 1973: NCHRP Report 153 – 16-page document, based on technical input from 70+ individuals and agencies and a special ad-hoc panel 1978: TR Circular 191 – addressed minor issues 1980: NCHRP Report 230 – 36-page document, brought procedures up to date with available technology and practices, updated the evaluation criteria 1993: NCHRP Report 350 – Comprehensive update of : Manual for Assessing Safety Hardware (MASH) 18

19 MASH Summary of Changes Test matrices and conditions Test matrices and conditions Test installation Test installation Test vehicle specifications Test vehicle specifications Evaluation criteria Evaluation criteria Test documentation Test documentation In-service performance evaluation In-service performance evaluation 19

20 Small car impact angle (20 degree to 25 degree). Small car impact angle (20 degree to 25 degree). Impact speed for single unit truck test (80 km/h [50 mph] to 90 km/h [56 mph]). Impact speed for single unit truck test (80 km/h [50 mph] to 90 km/h [56 mph]). Impact angle for terminals and crash cushions (20 degree to 25 degrees). Impact angle for terminals and crash cushions (20 degree to 25 degrees). Gating terminal/crash cushion (Reduce angle from 15 degrees to 5 degrees). Gating terminal/crash cushion (Reduce angle from 15 degrees to 5 degrees). Mid-size car test (Add 1500A test vehicle for staged impact attenuation devices). Mid-size car test (Add 1500A test vehicle for staged impact attenuation devices). 20 Test Matrices and Conditions

21 Barrier Testing Heights (Establish max. for small vehicle and min. height for pickup test) Barrier Testing Heights (Establish max. for small vehicle and min. height for pickup test) Critical Impact Points (CIPs) for reverse direction impacts Critical Impact Points (CIPs) for reverse direction impacts TMA optional tests to mandatory (Define max/min truck weight, control ballast shifting and vehicle braking) TMA optional tests to mandatory (Define max/min truck weight, control ballast shifting and vehicle braking) Variable message sign and arrow board trailers (Require same test criteria as TMAs) Variable message sign and arrow board trailers (Require same test criteria as TMAs) 21

22 Support structures and work zone traffic control devices (Add light truck test in addition to the small vehicle testing criteria) Support structures and work zone traffic control devices (Add light truck test in addition to the small vehicle testing criteria) Longitudinal channelizing barricades (Add new category and recommended test matrix) Longitudinal channelizing barricades (Add new category and recommended test matrix) EDR data collection (Provide data on impact conditions and accelerations from vehicle) EDR data collection (Provide data on impact conditions and accelerations from vehicle) 22 Test Matrices and Conditions

23 Test Installation Soil Condition (soil type, gradation, compaction and density) Soil Condition (soil type, gradation, compaction and density) Embedment of Posts (not necessary with reporting of soil conditions) Embedment of Posts (not necessary with reporting of soil conditions) Components (provide documentation of components used) Components (provide documentation of components used) Installation Lengths (document length of test installation) Installation Lengths (document length of test installation) 23

24 Test Vehicles Test vehicles (change small vehicle and pickup) Test vehicles (change small vehicle and pickup) Single unit truck mass (from # to #) Single unit truck mass (from # to #) Light truck test vehicle (Min. c.g. height of 28 inches) Light truck test vehicle (Min. c.g. height of 28 inches) Vehicle age (six years older or less) Vehicle age (six years older or less) Truck box attachment (limit detachment, reduce inconclusive testing results) Truck box attachment (limit detachment, reduce inconclusive testing results) Vehicle damage (document external vehicle crush damage using NASS procedures) Vehicle damage (document external vehicle crush damage using NASS procedures) Crushable nose characteristics (develop updated surrogate vehicle testing from 1981 Volkswagen Rabbit) Crushable nose characteristics (develop updated surrogate vehicle testing from 1981 Volkswagen Rabbit) TMA support vehicle (Report maximum weight of support vehicle) TMA support vehicle (Report maximum weight of support vehicle) 24

25 25

26 Evaluation Criteria Occupant risk (Modify calculations for Occupancy Impact Velocity and Ridedown Acceleration with vehicle yawing) Occupant risk (Modify calculations for Occupancy Impact Velocity and Ridedown Acceleration with vehicle yawing) Windshield damage (Provides more quantitative criteria; apply criteria to structural support devices the same for work zone devices) Windshield damage (Provides more quantitative criteria; apply criteria to structural support devices the same for 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 with exit box criteria) Exit conditions (Report lane intrusions and exit angle with exit box criteria) Vehicle rebound for crash cushions (reporting criteria) Vehicle rebound for crash cushions (reporting criteria) 26

27 In-Service Evaluation Encourage in-service evaluation to demonstrate satisfactory field performance. Encourage in-service evaluation to demonstrate satisfactory field performance. Pool resources (partnering) between State proprietary device manufacturers. Pool resources (partnering) between State proprietary device manufacturers. Disseminate information through resource channels like National Technical Information Services (NTIS), FHWA regional resource centers, and State pooled fund consortiums. Disseminate information through resource channels like National Technical Information Services (NTIS), FHWA regional resource centers, and State pooled fund consortiums. Consider the establishment of new national center on in-service evaluation. Consider the establishment of new national center on in-service evaluation. 27

28 Full Scale Crash Tests Under NCHRP 22-14(02) Conducted several full-scale crash tests of existing hardware, including: Conducted several full-scale crash tests of existing hardware, including: –Strong Post W-Beam System –Midwest Guardrail System –New Jersey Shaped Concrete Barrier –F-Shape temp. concrete barrier with 3-loop connection –Iowa Transition –Tangent Guardrail terminal –New Jersey Shaped Concrete Barrier (32 inches), failed TL-4 under MASH 28

29  All highway safety hardware accepted using criteria contained in NCHRP 350 may remain in place and may continue to be manufactured and installed.  Highway safety hardware accepted using NCHRP Report 350 criteria is not required to be retested or recertified using MASH criteria. 29 AASHTO/FHWA Joint Implementation Plan

30 If highway safety hardware that has been accepted by FHWA using criteria contained in NCHRP Report 350 fails testing using MASH criteria, AASHTO and FHWA will jointly review the test results and determine a course of action. If highway safety hardware that has been accepted by FHWA using criteria contained in NCHRP Report 350 fails testing using MASH criteria, AASHTO and FHWA will jointly review the test results and determine a course of action. Upon adoption of MASH by AASHTO, any new highway safety hardware not previously evaluated shall utilize MASH for evaluation and testing. Upon adoption of MASH by AASHTO, any new highway safety hardware not previously evaluated shall utilize MASH for evaluation and testing. 30 MASH Implementation

31 Any new or revised highway safety hardware under development at the time the MASH is adopted may continue to be tested using the criteria in NCHRP 350. Any new or revised highway safety hardware under development at the time the MASH is adopted may continue to be tested using the criteria in NCHRP 350. However, FHWA will not issue acceptance letters for new or revised highway safety hardware tested using NCHRP Report 350 criteria after January 1, However, FHWA will not issue acceptance letters for new or revised highway safety hardware tested using NCHRP Report 350 criteria after January 1, MASH Implementation

32 Agencies are encouraged to upgrade existing highway safety hardware that has not been accepted under NCHRP Report 350 or MASH: Agencies are encouraged to upgrade existing highway safety hardware that has not been accepted under NCHRP Report 350 or MASH: –during reconstruction projects, –during 3R projects, or –when the system is damaged beyond repair. 32 MASH Implementation

33 Highway safety hardware not accepted under NCHRP Report 350 or MASH with no suitable alternatives available may remain in place and may continue to be installed. Highway safety hardware not accepted under NCHRP Report 350 or MASH with no suitable alternatives available may remain in place and may continue to be installed. 33

34 Contact Information Keith A. Cota, Chairman AASHTO Technical Committee on Roadside Safety New Hampshire DOT Hazen Drive, PO Box 483 Concord, NH Tel:


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