U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
The AASHTO Manual for Assessing Safety Hardware (MASH) is the new state of the practice for the crash testing of safety hardware devices for use on the National Highway System (NHS). It updates and replaces NCHRP Report 350.
Source: FHWA
Testing criteria for highway roadside hardware have been in place since 1962. NCHRP Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features, has been the accepted method for safety hardware device testing and eligibility since 1993.
MASH presents uniform guidelines for crash testing permanent and temporary highway safety features and recommends evaluation criteria to assess test results. This manual is recommended for highway design engineers, bridge engineers, safety engineers, researchers, hardware developers, crash test laboratories, and others concerned with safety features used in the highway environment.
The need for updated crash test criteria was based primarily on changes in the vehicle fleet. Vehicles have increased in size and light truck bumper heights have risen since the NCHRP Report 350 criteria were adopted in 1993 (see chart for details).
MASH does not supersede any guidelines for the design of roadside safety hardware, which are contained in the AASHTO Roadside Design Guide.
Any new or revised highway safety hardware under development as of October 15, 2009, when the MASH was published, may continue to be tested using the criteria in NCHRP Report 350. However, FHWA will not accept or review requests for new or revised highway safety hardware tested using NCHRP 350 criteria which are received after January 1, 2011.
The FHWA Office of Safety considers that a 100 km/hr test is representative of worst case run-off-road crashes. Early on in the panel discussions related to the update of NCHRP Report 350, there was considerable discussion about the need to crash test at speeds over 100 km/h given that the posted speed limit of some highways is now above 65 mph. Based on data available to the research team it was concluded that, regardless of posted speeds, most impacts with fixed objects occurred at somewhat reduced speeds, likely due to pre-crash application of brakes.
Source: FHWA
For contracts on the National Highway System with a letting date after the dates below, only safety hardware evaluated using the 2016 edition of MASH criteria will be allowed for new permanent installations and full replacements:
| Topic | NCHRP 350 | MASH |
|---|---|---|
| Small car test vehicle | 820C vehicle (1,800 lbs.) | 1100C vehicle (2,420 lbs.) |
| Small car impact angle | 20 degrees | 25 degrees |
| Light truck test vehicle | 2000P vehicle (4,400 lbs.) | 2270P vehicle (5,000 lbs.) |
| Gating terminals and crash cushion impact angle | 15 degrees | 5 degrees |
| Variable message signs and arrow board trailers | No mention | Added to TMA crash test matrix |
| Support structure and work zone traffic control device testing | Only small car tested | Small car and light truck tested |
| Windshield damage criteria | Subjective/Qualitative | Objective/Quantitative |
| Vehicle rebound in crash cushion tests | None | Required |
Purchase MASH report from the AASHTO Bookstore: https://bookstore.transportation.org
FHWA Presentation on MASH (October 2009): http://fhwa.na3.acrobat.com/mashfinal
FHWA website on roadside hardware: http://safety.fhwa.dot.gov/roadway_dept/policy_guide/road_hardware
Nicholas Artimovich
FHWA Office of Safety
Roadway Departure Team
nick.artimovich@dot.gov
202-366-1331
Will Longstreet
FHWA Office of Safety
Roadway Departure Team
will.longstreet@dot.gov
202-366-0087
Dick Albin
FHWA Resource Center
dick.albin@dot.gov
(303) 550-8804
