Since 1990, the National Highway Traffic Safety Administration (NHTSA) implemented a dynamic side impact compliance test. This compliance test, Federal Motor Vehicle Safety Standard (FMVSS) No. 214, is a nearly right angle side impact in which the striking vehicle moves at 53.6 kmph into the struck vehicle. In 1997, NHTSA began testing passenger cars in side impact in the New Car Assessment Program (NCAP). In the USA NCAP side impact, the striking vehicle is towed at a 8 kmph higher speed than in the compliance test.

An analysis has begun on the data from the first NCAP side impact tests, thirty-two in number. In the crashes, accelerometers were installed in the door and door frames of the struck vehicle. Using the accelerometers on the vehicle structure and in the side impact dummy, the crash event was investigated. One tool used in the investigation was the velocity-versus-time diagram.

First, the crush of the interior door and its relationship to the severity of the occupant injury readings was examined. A correlation was found between the single independent variable, amount of the interior door crushed by the occupant, and the Thoracic Trauma Index. Second, the data was examined to determine the extent to which the pelvis of the dummy was loaded initially before loading the torso. A weaker correlation was found between the time duration (that the pelvis was loaded before the torso) and the Thoracic Trauma Index. Finally, the effect of the two independent variables together was examined.