Driver's Visual Performance in Rear-End Collision Avoidance Process under the Influence of Cell Phone Use

Rear-end crash is the most common type of on-road traffic crash, and cell phone use contributes to the increase of rear-end crashes. The effects of cell phone use on driving performance have been thoroughly investigated in previous research with various measurements. However, change in driver's visual performance while using a cell phone in situations with high rear-end risk has not yet been fully understood. This driving simulator study investigated drivers' eye movement performance in a rear-end collision avoidance maneuver during cell phone conversation. Eye movement data of 36 participants were collected in a car-following scenario featuring imminent rear-end collision. The whole collision avoidance process was divided into four stages for eye movement data analysis, including normal driving stage, brake response stage, deceleration adjusting stage, and speed recovering stage. Results showed that the average pupil size, fixation duration, and dwell time on the leading vehicle increased significantly during the brake response and deceleration adjusting stages. This indicated that the drivers' cognitive workload increased during these stages. Drivers used blink inhibition and quick saccade as a visual compensation strategy to mitigate the increased workload from cell phone use during the brake response stage. However, in the deceleration adjusting stage, the cell phone use condition led to a lower fixation frequency on the leading vehicle than in the no phone use condition. Professional drivers were found to pay more visual attention to the leading vehicle than non-professional drivers in the normal driving stage.