Abstract

The purpose of the present study was to investigate the effects of modality(auditory vs. visual) and complexity of information (high vs. low frequency) in a in-vehicle navigation system on drivers' information processing and vehicle control. In Experiment 1, the effects of information modality on free recall performance, driving performance, and subjective evaluation for the types of information were investigated. The results showed that (1) free recall performance was better in the auditory condition than in the visual condition, but (2) driving performance was better in the visual condition than in the auditory condition. In addition, (3) the drivers generally preferred visual information than auditory information. In Experiment 2, drivers' reaction time and accuracy were examined as information modality, frequency of information, and driving distance varied. The results showed as follows. (1) the drivers responded faster in the auditory information condition than in the visual condition. But (2) the auditory condition also led to increased reaction time as the amount of information increased. In contrast, (3) reaction time for the visual information increased as the driving distance increased. (4) The error rate did not appear to be affected by information modality, but a higher rate was found in the complex information condition (high frequency) and in the earlier part of driving.