PERIPHERAL VISUAL PERFORMANCE OF AUTOMOBILE DRIVERS IN A SIMULATED HIGHWAY ENVIRONMENT

This paper describes driving simulation studies of the effects of foveal search task demands and target visibility (contrast) upon detection of passing highway vehicles in the visual periphery. Visual scenes of freeway driving were simulated to cover a horizontal visual field of 100 degrees from the fixation point. A foveal task requiring different levels of visual search activity was provided. Ten subjects (6 young and 4 aged) were tested. For each subject, baseline data such as the normal visual field, threshold for visibility for stationary targets in the periphery and critical performance level on the foveal search task were gathered. Experiments were conducted to test the effect of three levels of foveal search task and three levels of target visibility on the peripheral detection angle of the subjects. Data on error rate and response times in the foveal task were also analysed. The results show that the foveal task loads simulating active search within a foveal region of 6 x 3 degrees do not seem to have an appreciable effect upon the detection of vehicles passing from behind. Target visibility was found to affect the peripheral detection angle more than any other variable. (a) Paper presented at the 7th Congress of the International Ergonomics Association held in Warsaw 27-31 August 1979. (TRRL)