A laboratory investigation of driver use of in-vehicle navigation systems is described in this paper. This study is the first phase of a two part project in which the second phase will apply the driver behaviour data to a traffic simulation model. The objective of the driver behaviour experiment was to compare the effect of four navigation systems on driver diversion decisions when faced with traffic congestion. Three of the systems were developed on the basis of a heading-up map display. These systems varied from a basic map with vehicle position information to a highly complex map with position, congestion, and route guidance information. The fourth system consisted of simplified symbolic directions and distance to change information. The experiment simulated typical freeway trips using sequences of slides of real freeway scenes and auditory feedback controlled by a computer. Drivers were presented information on traffic congestion, vehicle speed and guide signs of off-ramps, and were motivated with monetary rewards and penalties to encourage diversion decisions that would minimise trip travel delays. In addition to several in-vehicle navigation system configurations, experimental variables included driver route familiarity, age group, and either commercial or noncommercial driving experience. The results showed that navigation system characteristics can have a significant effect on driver diversion behaviour, with better systems allowing more anticipation of traffic congestion. This result was found over several different levels of congestion. Driver age also was a factor, with old drivers more reluctant to divert from the main freeway route. Route familiarity, commercial driving experience, and gender group variables were not significant factors in driver diversion decision making. This paper appears in Transportation Research Record No. 1306, In-vehicle Information Systems: modelling Traffic Networks and behavioural Considerations 1991.
Samenvatting