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In France, as in other countries, accident research studies show that the greatest proportion of restrained occupants sustaining severe injuries and fatalities are involved in frontal impact (70% and 50% respectively). In severe frontal impacts with restraint occupants and where intrusion is not preponderant, the oldest occupants very often sustain severe thoracic injuries due to the seat belt. In the seventies, a few cars were equipped in France with load limiters and it was thereby possible to observe a relationship between the force applied and the occupant's age with regard to this thoracic risk. The reduction of intrusion for the most violent frontal impacts, through optimization of car deformation, usually translates into an increase in restraint forces and hence thoracic risks with a conventional retractor seat belt for a given impact violence.

The goal of this paper is to examine the validity of the Crashworthiness Rating Method (part of the New Car Assessment Program -NCAP - created by NHTSA) with reference to real-life accident data. A program was set up to verify the quality of predictive characteristics of vehicle models' real passive safety protection based on 35 mph crash tests against a 0° barrier. The Crashworthiness Rating Method was applied in the French context because seat belt use has been mandatory in France for over 10 years, and we have access to real-life accident files whose size and categories (type of vehicle model, crushed area, obstacle struck, seat occupied, age, and use of seat belt) allowed us to select cases appropriately and thoroughly. Additionally, the vehicle models which are representative of the French vehicle fleet were tested as if they were part of the NCAP.

This study is related to the modifications of Part 572 dummy for lateral impact, to aid in the evaluation of the injury reducing potential of automotive lateral protection systems. This was done by modifying the rib cage, arms and shoulders of Part 572 so that its impact performance more closely simulates that of a human. According to biomechanical data coming from cadaver testing, the arm was modified by reducing the size of the structural members and increasing the padding of the arm; the mobility of the shoulder was increased in both forward and upward directions. Moreover, the shoulder was modified to become transversely collapsible to a certain extent. The rib cage was redesigned so as to give a more realistic deformation. The measurement of lateral chest deflection was also incorporated into the rib cage design. The frontal impact characteristics of the dummy, both for impact and belts, were left unchanged.