Driving errors and gaze behavior during in-vehicle object and spatial distractions

Abstract

Driving is a complex task performed in a dynamic environment whereby visuospatial information is a critical aspect of driver cognition. Drivers’ interaction with the in-vehicle interfaces challenges their ability to respond to the dynamic traffic scenes efficiently. This study examines the effect of in-vehicle object and spatial distractions on drivers’ gaze behavior and driving performance. An experimental paradigm named as direction following in distracted driving – object and spatial (D3-OS) was developed for this study. An instrumented vehicle was voluntarily driven by 47 drivers on a two-lane test-track (data from seven participants were invalid, hence not included in the analysis). Four direction signboards were installed on the left side along the track and the drivers were required to drive according to the directions displayed on these signboards. Drivers were instructed to provide responses to the distracting stimuli shown on an in-vehicle display monitor that was attached to the dashboard. Novice and expert drivers (20 in each group) were randomly assigned to object and spatial distractions. The results demonstrate that compared to spatial distraction, during object distraction, fixation durations and fixation counts on area of interest (AOI) are significantly reduced and driving errors (i.e., both slips and lapses) are significantly increased. Novice drivers committed significantly more slips and lapses as compared to expert drivers. Furthermore, an increased cognitive workload (CWL) is associated with an increase in the occurrence of slips and lapses. On the whole, the results of the study signify the importance of strict enforcement of traffic regulations related to distracted driving more stringently in the case of novice drivers.