Crash tests of side impact air bags show they can help prevent serious head injuries, even in collisions between passenger cars and high-riding light trucks, insurance industry researchers report, according to Associated Press (AP). In its first such tests, the Insurance Institute for Highway Safety rammed a pickup truck travelling at 32 mph into the side of a Volvo S80 going 16 mph and found the car's side air bags protected the crash dummy's head against what could have been a fatal head injury.