Is the Eye Movement Pattern the Same? The Difference Between Automated Driving and Manual Driving

Abstract

This driving simulator study was conducted to investigate the drivers’ eye movement pattern in automated and manual driving condition, and examine which ocular metrics are effective to evaluate the vigilance (response task) of drivers when they in a state of fatigue. Images of drivers’ eye movement were recorded in both conditional automated and manual driving conditions. Ocular metrics such as horizontal eye activity, vertical eye activity, PERCLOS and time of each eye closure (TEEC) were obtained from the images, and the metrics were averaged in a 5-min period with the label of fatigue level (Karolinska Sleepiness scores). Using a within-participant design, twenty participants experienced automated and manual driving with response tasks. Results of the study showed that drivers’ horizontal and vertical eye activity were generally higher than that observed during manual driving when drivers in some signs of sleepiness. However, with the deepening of fatigue, drivers’ eye activity decreased significantly in automated driving condition, but a sustainable effect was found in manual driving. Interestingly, the ocular metric of TEEC seems more accurate to evaluate the vigilance of drivers than PERCLOS in automated driving condition. Therefore, decreasing the time of each eye closure seems a useful way to increase the vigilance of drivers.