The Institute’s frontal test is based on 40 mph frontal offset impact. Each vehicle’s evaluation is based on measurements of intrusion into the cabin, injuries recorded on a crash test dummy and analysis of slow-motion film to assess the restraint system. Side impact ratings are based on performance in a crash test in which the side of a vehicle is struck by a barrier representing the front end of a pickup or SUV, moving at 31 mph. Ratings reflect injury measures recorded on two instrumented dummies, assessment of head protection, and the vehicle’s structural performance. Rear crash protection is done by simulating an impact at 20 mph and is rated according to the height of a restraint and its horizontal distance behind the back of the head of an average size man.