Driver Reliability Requirements for Traffic Advisory Information
Barry H. Kantowitz
Richard J. Hanowski
Susan C. Kantowitz
Battelle Human Factors Transportation Center, Seattle
Transportation engineers would like to provide reliable traffic information to motorists, but there are many perturbations in the highway system that make it difficult to achieve this goal. Congestion, delays, and accidents combine so that the information provided to motorists may no longer be entirely accurate when it is received. Although it seems reasonable to suspect that unreliable information causes drivers to discount or even to ignore posted traffic messages (e.g., on road signs), there are little empirical data concerning how reliable the information should be. In some domains, even a single incident is sufficient to extinguish behavior (as when a vending machine fails to operate). How many people continue putting coins into defective parking meters? Other systems may be more robust. Will drivers tolerate some errors in route guidance systems without losing trust ( Lee & Moray, 1991) and ignoring the information provided?
An important goal of Advanced Traveller Information Systems (ATIS) is to allow travellers to drive safely and efficiently by providing real-time route guidance and traffic advisory information. Because the impact of ATIS on driver behavior is not yet fully understood, human factors research is required to fill this gap. Before describing the results of two ATIS-related experiments conducted at the Battelle Human Factors Transportation Cen-