A Car-Following Model Relating Reaction Times and Temporal Headways to Accident Frequency

This paper deals with a car-following model relating driver reaction time, temporal headway and deceleration response to accident frequency. The central goal is to assess the sensitivity of collision probability to a shift in expected reaction time. This problem reduces to determining the sensitivity of the probability of ruin to changes in the drift of the process of cumulative differences between reaction times and temporal headways. A diffusion-type approximation is used and it is shown that additive changes in mean reaction time correspond to multiplicative changes in collision probability. A numerical example is given to illustrate the potential effects of a mere 0.1 sec decrease in mean reaction time.