Underride guards on most big rigs leave passenger vehicle occupants at risk in certain crashes

Modern semitrailers for the most part do a good job of keeping passenger vehicles from sliding underneath them, greatly increasing the chances of surviving a crash into the back of a large truck, recent tests by the Insurance Institute for Highway Safety (IIHS) show. But in crashes involving only a small portion of the truck’s rear, most trailers fail to prevent potentially deadly underride