The National Highway Traffic Safety Administration is upgrading safety standards on rear underride protection on tractor trailers to help prevent crashes involving passenger vehicles, but safety advocates say the changes do not go far enough.
Rear underride crashes occur when a passenger vehicle strikes the back of a generally larger vehicle and the front end of the passenger vehicle slides under the rear end of the larger vehicle.
In extreme underride crashes involving tractor trailers, the passenger vehicle can underride the trailer to such an extent that the end of the trailer enters the passenger compartment of the colliding vehicle, severely injuring or killing occupants of the car. Underride guards mounted on the rear of trailers can prevent underride and serious injuries and death.
