MOVING FROM MEASURES OF PERFORMANCE TO MEASURES OF EFFECTIVENESS IN THE SAFETY EVALUATION OF ITS PRODUCTS OR DEMONSTRATIONS

The purpose of this paper is to address issues associated with converting practical measures of performance to measures of metrics of the safety impact of intelligent transportation system (ITS) products and demonstrations. For the purpose of this discussion, the dependent measures associated with driving will be termed "measures of performance" and the associated constructs with theoretically impact driving safety will be termed "measures of effectiveness." The paper focuses on the empirical, proactive evaluation of ITS safety prior to fleet-type evaluation studies and, ultimately, mass deployment. Therefore, the methods described in this paper attempt to predict safety utilizing measures that are removed from the direct, epidemiological assessment of safety (i.e., numbers of crashes), since achieving sample sizes to accurately predict actual crash rates is often impractical.