In its course of development passive safety has reached a high standard. Vehicle structures guarantee acceptable decelerations of the meanwhile stiffed car compartment; the car interior has been defused by paddings and an adequate styling and the restraint system has been equipped with modern and efficient subsystems.
Just the first glance to up-to-date real-world accident statistics and to the development of traffic accidents over the years makes clear that this high standard in vehicle safety reflects in a reduced number of occupant injuries. The number of occupants with fatal injuries in traffic accidents in the FRG may here serve as an example. The period from 1970 to 1992 saw a reduction of casualities from about 19.000 to about 7.000 people. In the annex figure 1 illustrates this development. Considering resultant costs from injuries the effects of improved vehicle safety become even clearer.In a study  H. Appel included resultant costs from injuries into a safety index and analyzed them for the years 1960 to 1990 for the FRG. As a result he observed an improvement of this safety index by the factor 4.
A detailed analysis of the latest statistics, however, reveals that there are still accident fields with a high number of severe injuries.This study particularly deals with thorax injuries, the reasons for the observed frequency and severity of such injuries and with measures to be taken in the passive safety system to ease or even avoid specific restraint system loadings.