Behavioral Indicators of Drowsy Driving: Active Search Mirror Checks

Driver impairment due to drowsiness or fatigue has a significant impact on the safety of all road users. Assessing an impairment such as driver drowsiness through the use of vehicle-based technology continues to be an area of interest. Both the initial detection and continued monitoring of driver drowsiness have been the emphasis of vehicle-based driver monitoring systems (DMS). Particularly, in-vehicle eye tracking systems have been implemented as a way of determining driver state. Specifically, when hands-free driving assistance features are engaged, measures such as the driver’s percentage of eye closure (PERCLOS) are being considered to determine driver drowsiness. However, one challenge of such a metric is its reliability, particularly with regard to false alarms (when a DMS indicates the driver is drowsy but in fact is not). Therefore, the use of more gross-level driver behavioral measures may serve as a way of cross-checking the assessments of a DMS. This work mined an available dataset in order to examine driver search behavior, with the goal of identifying relationships between driver vigilance and drowsy driving, to test the hypothesis that driver search behavior (e.g., mirror checks) degrades with increasing levels of drowsiness. Based on a statistical comparison of participant driving data encompassing instances of alert, moderately drowsy, and drowsy driving, no significant differences were observed among these three classifications.