MASH presents uniform guidelines for crash testing permanent and temporary highway safety features and recommends evaluation criteria to assess test results. MASH updates and replaces NCHRP Report 350. 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. Products addressed in MASH include longitudinal barriers, transitions, end terminals, crash cushions, breakaway supports, truck mounted attenuators, and work zone traffic control devices. The crash performance is judged on structural adequacy, occupant risk, and vehicle trajectory.


Significant Changes between NCHRP 350 and MASH

Topic NCHRP 350 MASH
Small car test vehicle 820C vehicle (1,800 lbs.) 1100C vehicle (2,420 lbs.)
Small care impact angle 20° 25°
Light truck test vehicle 2000P (4,400 lbs.) 2270P (5,000 lbs.)
Gating terminals and crash cushion impact angle 15° 5° - 15°
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 care tested Small car and light truck tested
Windshield damage criteria Subjective/Qualitative Objective/Quantitative
Vehicle rebound in crash cushion tests None Required

For More Information


NCHRP 350 Sunset

On November 12, 2015, FHWA issued a memorandum indicating that all modifications to NCHRP 350-tested devices will require testing under MASH in order to receive a Federal-aid eligibility letter from FHWA. In addition, a Federal Register Notice was also issued regarding this action. This has provided a significant step toward the implementation of MASH.

December 31, 2017
W-Beam Barriers and cast-in-place Concrete Barriers.
June 30, 2018
W-Beam Terminals
December 31, 2018
Cable Barriers, Cable Barrier Terminals, and Crash Cushions
December 31, 2019
Bridge Rails, Transitions, All other Longitudinal Barriers (including portable barriers install permanently), all other Terminals, Sign Supports, and all other breakaway hardware