The Use of Accident Data in Studying Vehicle Handling Performance

Abstract

A study to establish the relation between vehicle handling performance and accident causation. Since deficiencies in handling are likely to be associated with accidents involving loss of control, measures of handling which are likely to express proneness to loss of control are first suggested; emphasis is placed on simplicity of measurement to allow as many different models of car as possible to be included in the study. Accident rates for the various types of accident which are likely to be influenced by these parameters are then determined by model of car. The effect of other factors, such as variation in driver characteristics between different models of car on these rates is then assessed so that the relation between handling characteristics and accident frequency can be defined. Finally, the relative importance of the various measures of handling suggested are assessed. The results suggest that there is a definite relation between handling performance and accident causation although it is relatively small when compared to driver effects. In explaining the variation in the accident rate between different models of car, driver effects account for as much as 70 per cent; if driver effects are removed from the accident rate then handling parameters explain between 35 and 40 per cent of the remaining variation between models of car. The important parameters appear to be weight, a measure of the change in understeer as a function of lateral acceleration and power to weight ratio.