Comments on the Highway-Crossing Problem

A discussion is given of the gap acceptance problem confronting a driver at a stop sign who is attempting to cross a single lane of traffic. This problem is discussed in the light of a gap acceptance probability that is taken in the form α(t) = 0 when t < T and 1 − α(t) = exp[−λ(t − T)] when t > T, rather than a step function as has been considered in the past. Some experimental information is discussed concerning the values of the parameters λ and T in such situations. This information coupled with theoretical considerations allows one to estimate quantities such as mean delay time, probability of zero delay, and highway transparency. Comments are made concerning the influence of car performance on road crossing and on entering highways.