October 18th, 2011
MASH UPUncategorized, by Catherine Higgins.
The Manual for Assessing Safety Hardware updates the size of test vehicles to more closely match what’s on the road today.
All permanently installed and temporary roadside hardware – including sign bases, crash cushions, traffic control devices, and various kinds of barriers, is crash tested according to standards established by the National Cooperative Highway Research Program. New standards for crash testing have recently gone into effect, and are detailed in AASHTO’s Manual for Assessing Safety Hardware. The new manual replaces NCHRP Report 350.
This video shows crash testing using MASH standards.
The MASH updates protocol for vehicles that are used in crash tests to more closely match what’s on the road today. The new crash test criterion is being used on all roadway hardware being produced since January 2011. NCHRP Report 350-tested hardware is appropriate when replacement is necessary, and re-testing is not required. UDOT will update roadway hardware with MASH tested products as necessary – the old hardware in place now is safe.
Although crash testing took place as early as the 1930’s, standards that establish criteria for tests have been in effect since 1962 with sedans specified as a test vehicle. As crash testing has continued through the years, understanding about the practice has improved and updates that add more criteria and different procedures have been added. For example, a 1974 NCHRP update added a small car and also added tests for transitions, terminals, crash cushions and breakaway supports. A 1980 update added evaluation criteria and modernized procedures to conform to available technology and practices. In 1993, a pickup was added as a test vehicle to represent small trucks and minivans in use.
The Texas Transportation Institute is one of the first organizations to crash test hardware, including sign bases and crash cushions. The TTI facility, a decommissioned military air base, has long concrete runways that make a good setting for the tests. The modern TTI crash test video below shows a crash test of a concrete barrier on a mechanically stabilized earth wall using the larger truck specified by the new MASH standards for vehicles.
Download the MASH.
Read a recent post about tests on MSE walls.
See an interactive timeline about crash testing at TTI.
Watch a presentation about how crash test standards have changed.