This paper presents information on analytical procedures being developed by the National Highway Traffic Safety Administration (NHTSA) to assess the safety problem associated with occupants of passenger cars involved in frontal impacts. This analytical assessment started with the characterization of a baseline vehicle fleet consisting of specific make/model passenger car groupings representative of the in-use fleet in the United States. Newly developed analytical models have been developed and are being run in an automated mode simulating these vehicles in different frontal crash configurations. The output of these automated runs includes measures of injury severity and cause of injury, and is being used to identify the effect of different vehicle attributes on injury causation. Preliminary analytical results are presented on the relationship between steering assembly structural attributes and injury severity. Comparisons of the fleet simulation results and accident data from the National Crash Seventy Study (NCSS) and the National Accident Sampling System (NASS) are also presented.