There seems to be no doubt of the efficacy of the several interior protection modifications of the modern American car. Their usefulness can be demonstrated in analysis, in simulations, and in clinical accident investigations.

Ultimately, however, there should be indication of their value in the mass accident statistics. While these totals are greatly affected by factors such as increasing traffic volume, certain sub-sets of the accident data should be more sensitive to the vehicle improvements. This paper presents a model which relates specific improvements to specific accident events in order to measure the effectiveness of vehicle modifications.

The data base for this study is a set of some 15,000 Michigan fatal accidents which occurred over the past six years. A flexible analysis system permits this data to be sorted with respect to accident type, car model year, and many other factors. This paper presents the results of such an analysis.