Naturalistic observation of drivers’ hands, speed and headway

Abstract

► Naturalistic observation of hands positions tested for reliability and construct validity. ► Speed and headway are compared to hands positions. ► Hands position correlates with speed and headway. ► Hands positions observations are reliable across locations and times. Drivers’ hands position have been shown to vary with traffic speed and complexity of the driving environment, such that drivers are more likely to place two hands on the top half of the steering wheel as the supposed driving difficulty increases (Walton, D. & Thomas, J. A. [2005]. Naturalistic observations of driver hand positions. Transportation Research Part F, 8 , 229–238). This research evaluates drivers’ hands positions, examining the reliability of the measure and the relationship between the positions of the driver’s hands, vehicle speed, vehicle headway and driver sex. The findings show that the observed positions of drivers’ hands have good inter-rater reliability and demonstrate both temporal and contextual reliability. The positions of drivers’ hands are related to other measures, such that drivers with lower-ranked positions of hands are more likely to travel at higher speeds and accept shorter headways. Female drivers are found to be 2.87 times more likely than males to place two hands rather than one hand on the top half of the steering wheel.