The National Highway Traffic Safety Administration (NHTSA) has tested 12 current production cars in a series of controlled side impacts. As measured by the impact responses of NHTSA side impact dummies, the cars were found to vary dramatically in their capability to provide occupant protection. For the median-aged side-struck occupant, the potential for serious thoracic injury was found to range from a low of 9 percent for the 4-door AMC Concord to a high of 97 percent for the 2-door Nissan Sentra.

This paper investigates these differences in safety performance and reports those vehicle design parameters that are key to thoracic side impact protection. From the available data, the study concludes that the design parameter most crucial to occupant protection in side impacts is the Door Effective Padding Thickness (DEPTH).