Response Times and Traffic Sign Design: Application of the Critical Path and OP Methods

In many situations a rapid, accurate response to a traffic sign is required. The design of traffic signs which keeps response time at a minimum is an important human factors problem. An understanding of the network of cognitive processes that govern response times can be very useful to the human factors engineer, especially when it is possible to determine which processes, if shortened in duration, would lead to an overall decrease in response time. The design activity can then be focused on keeping at a minimum the duration of these critical processes. Two recently developed methods of response time analysis which make possible the determination of the critical processes are discussed: the critical path method (Schweickert, 1978) and the OP method (Fisher and Goldstein, in press).