In-car electronic route guidance systems are presently in development and are likely to be introduced in the nineties. It is often assumed that auditory presentation of navigation information is preferable because of the existing visual load of the driving task. The aim of the present study was to (a) create a theoretical frame of reference; and, (b) to compare visual and auditory information presentation with respect to their effect on driving behaviour and mental load in real driving conditions. Moreover, both electronic systems were compared with the conventional way of navigation, i.e. with a commercially available map. From theoretical considerations it was suggested that auditory information is better suited to drivers who are inexperienced with the use of in-car route guidance. With experience, however, drivers might be able to integrate intake of visual information with driving, thus increasing their performance. The empirical study showed slightly better driving performance for auditory information under average driving conditions. It was also demonstrated that electronic guidance systems are especially useful if drivers are unused to navigation, on complex routes and with high traffic density. Because of confusion between the speed, modality and format of information, further research should be carried out on these variables under highly demanding conditions with a large variety of subjects. (Author/publisher)
Abstract