Underride guards fail even at low speeds

The Insurance Institute for Highway Safety has asked federal officials to require greater rear impact protection for commercial trailers.On Feb. 28, the group of insurance companies and associations petitioned the National Highway Traffic Safety Administration to upgrade Federal Motor Vehicle Safety Standards for underride guards, which are meant to prevent a car sliding under a truck or trailer in a crash.

Of course, some trailers are better than others, but there is no testing standard for evaluating the underride guards and their attachment points and hardware. Despite this, there is a federal safety standard for the guards, and there’s also a more stringent Canadian specification that requires the guards to be stronger and absorb more crash energy.

Despite major advances in passenger car safety since the mid-1970s, it seems the guards on tractor trailers still fail to reliably prevent vehicles from sliding under trailers in the event of a collision – a similar result to studies conducted over 30 years ago.In analyzing the Large Truck Crash Causation Study, a federal database of about 1,000 actual crashes from 2001-2003, the Institute determined that of the 115 crashes where a passenger vehicle struck the rear of a truck or semi, nearly 80 percent involved underride, and nearly half of those vehicles suffered severe or catastrophic damage.
However, it concluded the decrease was not statistically significant. The Fatality Accident Reporting System does not list trailer model years, so conclusions could not be drawn from this data either, the researchers said.