Presentation on theme: "M.A.S.H.: The New Safety Hardware Crash Testing Criteria Idaho Transportation Department 2011 Project Development Conference Richard Albin Federal Highway."— Presentation transcript:
M.A.S.H.: The New Safety Hardware Crash Testing Criteria Idaho Transportation Department 2011 Project Development Conference Richard Albin Federal Highway Administration Resource Center Safety and Design Team April, 2011
Crash Testing - History Crash Testing has been used as a tool for evaluating the safety performance of roadside features for many years.
History of Testing Procedures Highway Research Correlation Services Circular 482 (1962) NCHRP Report 153 (1974) NCHRP Report 230 (1980) NCHRP Report 350 (1993) Procedures for how to perform crash tests have evolved
NCHRP 350 NCHRP Report 350, was formally adopted by FHWA for the NHS This was the first time that FHWA adopted these procedures An implementation date was established in 1998 for new installations on the NHS.
Practical Worse Case Philosophy
Test Matrix NCHRP Report 350 created 6 Test Levels Levels 1-3 based on speed TL1 – 50 km/h (31 mph) TL2 – 70 km/h (43 mph) TL3 – 100 km/h (62 mph) Levels 4-6 add large trucks
Manual for Assessing Safety Hardware (MASH) Update of the evaluation procedures prepared Published as AASHTO document in October, 2009 Implementation plan also developed
Manual for Assessing Safety Hardware (MASH) Primary Focus of Update Update test vehicles & impact conditions Eliminated ambiguities Removed inconsistencies Consolidate test matrices Tighten reporting procedures
Most Significant Changes Small car and Pickup mass increased TL-4, single unit truck test revised Impact angle for small car increased to 25 o Impact angle for terminals and crash cushions raised to 25 o
Small Car The 820C vehicle specified in Report 350 has not been manufactured since 2000. Proposed vehicle is a 1100C (2420 lb) 2001-2003 models curb weight - 2,765 lb
Small Car Angle Increase impact angle from 20 degrees to 25 degrees to be consistent with Pickup test Tested with new impact vehicle and angle into a rigid NJ shaped concrete barrier
Pickup Truck The 2000P Pickup specified in Report 350 has not been manufactured since 2001 Quadcab reflects the 90th percentile vehicle Proposed vehicle is a 2270P Quadcab Pickup (5000 lbs) Quadcab Pickup has a higher center of gravity and more closely represents the large SUV’s
Pickup Truck How does w-beam guardrail (27-5/8” height, steel posts) perform with large vehicle?
Pickup Truck How does w-beam guardrail (27” height, wood posts) perform with large vehicle?
Impact Angle for Terminals and Crash Cushions The angle of impact for the Length Of Need (LON) test for barrier terminals and crash cushions was increased from 20 degrees to 25 degrees for consistency with LON and Transition tests Impact angle for the end-on test of gating terminal decreased from 15 degrees to 5 degrees as it is more critical 25 55
New Test Matrices added Variable Message Sign / Arrow Board test matrix added. Longitudinal Channelizing Devices category added.
Test Matrices revised Pickup Truck Test was added for support structures and work zone traffic control devices
Test Installations Installation length more definitive (cable barriers 600 ft minimum). Specified the critical impact point for cable barrier testing to be at a post for the pickup truck test
Test Installations Barrier height (max) small car & (min) pickup test. Addition of performance based specs for soil.
Evaluation Criteria Windshield damage criteria to be more objective. Occupant compartment deformation criteria more objective and based on NHTSA data Maximum roll angle set to 75 degrees.
Single Unit Truck Test (TL-4) NCHRP Report 350, the impact severity of the SU test (TL-4) is less than the impact severity of the Pickup test (TL-3) Intent was to make the TL-4 test more meaningful. NCHRP 350 MASH
Single Unit Truck Test (TL-4) Mass increased from 8,000 kg (18000 lb) to 10,000 (22,000 lb) Speed increased from 80 km/h (50 mph) to 90 km/h (56 mph) 32” New Jersey shaped concrete barrier
Single Unit Truck Test (TL-4) 36” Single Slope concrete barrier
What did not change? Impact speed for high speed test retained at 100 km/h (62 mph) No Changes to TL-5 and TL-6 Angle for strength test Six test levels
Tests Conducted with New Criteria W-Beam Guardrail – Steel Post (27-5/8” height) Pickup (passed) W-Beam Guardrail – Wood Post (27” height) Pickup (failed)
Tests Conducted with New Criteria Box-Beam Guardrail Pickup (passed) Weak Post W-Beam Pickup (passed) Midwest Guardrail (31” height) Pickup (passed) Small Car (passed)
Tests Conducted with New Criteria W-Beam Guardrail Median Barrier Pickup (failed) Small Car (passed) Thrie Beam Guardrail Barrier Pickup (failed) Guardrail Transition Pickup (passed) Guardrail Terminal (SKT) CIP test with small car (passed)
Tests Conducted with New Criteria Rigid 32” NJ shape concrete barrier Small car (passed) Single Unit Truck (fail as TL-4) Precast Concrete Barrier (Iowa F Shape) Pickup (passed)
Tests Conducted with New Criteria U Channel sign support Pickup (passed) Perforated square tube sign suppost Pickup (failed)
MASH Implementation Plan AASHTO Technical Committee on Roadside Safety (TCRS) is responsible for developing and maintaining MASH. FHWA shall review and accept highway safety hardware under MASH.
MASH Implementation Plan All hardware accepted under Report 350 may remain in place and may continue to be manufactured and installed. Hardware accepted using Report 350 is not required to be retested using the MASH criteria
MASH Implementation Plan However … If hardware that met Report 350 is tested and fails using MASH… AASHTO & FHWA will jointly review results and determine a course of action.
MASH Implementation Plan Upon adoption new hardware not previously evaluated shall utilize the MASH criteria Hardware under development at time of AASHTO adoption can be completed under Report 350 FHWA will not consider applications for acceptance under Report 350 after January 1, 2011.
MASH Implementation Plan Hardware installed on new or reconstruction projects shall meet Report 350 or MASH Agencies are encouraged to upgrade hardware that does not meet Report 350 or MASH when: roadway is reconstructed 3R projects System damaged beyond repair
MASH Implementation Plan Hardware not meeting either Report 350 or MASH and for which there are no suitable alternatives can remain in place and can continue to be installed.
Contact Information FHWA Office of Safety Nick Artimovich Phone:202-366-1331 Email: email@example.com@dot.gov FHWA Office of Safety Will Longstreet Phone: 202-366-0087 Email: firstname.lastname@example.org@dot.gov FHWA Resource Center Dick Albin Phone: 303-550-8804 Email: email@example.com@dot.gov FHWA Roadside Hardware Link http://safety.fhwa.dot.gov/roadway_dept/policy_guide/road_hardware/
A narrated presentation can be viewed by following this link: https://admin.na3.acrobat.com/_a55098539/mashfinal/https://admin.na3.acrobat.com/_a55098539/mashfinal/