The improvement in crash resistance in the underride guards is welcome, as the Insurance Institute for Highway Safety (IIHS) previous test in 2010 was disappointing. Even the best trailer tested only worked when vehicles struck the trailer in the center.
What are known as offset crashes, which are very common in the real world of truck crashes, saw none of the trailers fare very well. Or more accurately, none of the crash test dummies would have fared very well had they been real crashes.
This month, the IIHS reported that in new tests the Vanguard trailer that had failed previous tests showed a big improvement. The IIHS notes this is the second trailer manufacturer to produced strengthened models in response to their tests, as Hyundai Translead made changes to their trailer, which had been the worst performer in the original series of tests.
It was able to pass the full-width and the 50-percent overlap test after the redesign. The IIHS notes, however, that even the Canadian standard, which is currently more rigorous than the U.S. requirements, is not adequate, when tested at a 30-percent offset, which still produced “severe underride.”
They point out that the National Highway Traffic Safety Administration (NHTSA) is working on a new standard for underride guards. The IIHS had asked NHTSA to propose more stringent standards back in 2011.
The current standards use a 35 mile per hour crash test. As part of the rulemaking, NHTSA should consider the possibility of increasing the something closer to highway speeds, as vehicles truck crashes on interstate highways may involve vehicles with speed differentials greater than 35 mph.
Whatever the proposal, it is likely that the trucking industry will oppose and delay any implementation for many years.
Insurance Institute for Highway Safety, “On guard: Safety gear on the back of truck trailers is improving,” October 9, 2014