Intelligent route guidance: will the new horse be as good as the old?

The human factors of intelligent automobile displays were investigated with emphasis on determining the need for design guidelines. The experiment was designed to examine the relationship between drivers´ visual attention and performance under concurrent multitask conditions. Twenty young male and female students with normal vision and a minimum of three years´ driving experience were assigned randomly to two groups in a mixed, three-factor experiment. Subjects drove in a moving-base simulator and performed cognitive tasks on a CRT display located on the instrument panel. A spatial perception task and a verbal memory task were designed to place differential demands on cognitive resources. Subjects were instructed to perform their best on the display and driving tasks, giving priority to the driving. Eleven dependent variables provided measures of driving performance, attentional behavior, display task performance, and workload. On-line eye movement sampling indicated whether the subject looked at the roadway or at the computer display. The results indicate that intelligent displays in vehicles can intrude on driving despite the mitigating influence of driver adaptation. Simulation was found to be a sensitive and valid technique for studying human factors issues related to the design of such displays. Intermediate attention variables, more sensitive to experimental manipulations than primary task measures, appear to provide a valid basis upon which ergonomic criteria could be developed.<>