March 1, 2011 — Following new crash test analysis, the Insurance Institute for Highway Safety is petitioning the federal government to require stronger underride guards on large semi trailers.
The guards, which hang below the rear of a trailer, are the main countermeasure for reducing injuries and deaths from vehicles crashing into the rear of a semi. Recent tests have indicated that the guards can fail in low-speed crashes, according to the institute.
The institute analyzed case files from a federal database of roughly 1,000 real-world crashes from 2001 to 2003. Of the 115 crashes involving a vehicle striking the back of a semi trailer, 78 percent resulted in the vehicle sliding under the trailer. In 23 of the 28 cases in which someone died, the entire front end of the vehicle slid under the truck.
The institute also conducted its own crash tests, evaluating three rear trailer guards that met U.S. rules. Two of the trailers also met stricter Canadian rules. When slammed with a 2010 Chevrolet Malibu traveling at 35 mph, one of the Candian-approved trailers, made by Wabash National Corp., prevented underride, but only when hit in the center of the guard. Other tests showed underride to some degree in every other instance, for every trailer.
“Cars' front-end structures are designed to manage a tremendous amount of crash energy in a way that minimizes injuries for their occupants,” said Adrian Lund, president of the institute. “Hitting the back of a large truck is a game changer. You might be riding in a vehicle that earns top marks in frontal crash tests, but if the truck's underride guard fails—or isn't there at all—your chances of walking away from even a relatively low-speed crash aren't good.”
Lund said regulatory gaps have allowed many heavy trucks to operate without any rear guards at all. He’s hoping the institute’s petition will be taken seriously, and result in stricter, safer rules.
