The Impact of Cognitive Distraction on Driver Perception Response Time Under Different Levels of Situational Urgency

Identifying drivers' perception response time (PRT) is of utmost importance for the development of rear-end collision alarm systems. However, the effects of cognitive distraction on PRT under different levels of situational urgency are unclear. Therefore, the purpose of this study was to quantify and compare the effects of cognitive distraction for both high and low situational urgency. Participants (N = 45) were presented with a simulated car-follow scenario. The effects on both perception time and movement time were analyzed separately under headways of 1.5s and 2.5s using the Bayes factor approach, and a mixed-effects model was constructed to calculate the magnitude and significance of effects of cognitive distraction and situational urgency on PRT. The results revealed (1) the effect on perception time was smaller in the high situational urgency condition, and a high probability of distraction-related delay on perception time was found in both high (BF
₁₀
= 15.588) and low (BF
₁₀
= 23.203) situational urgency conditions; (2) the effect on movement time was larger in the high situational urgency condition, and the delay of movement time was more likely to occur in the high (BF
₁₀
= 19.642) situational urgency condition than in the low (BF
₁₀
= 0.493) situational urgency condition; (3) cognitive distraction increased driver's PRT by 1.556s, the average of drivers' PRT decreased by 0.241s for every 1s reduction in initial time headway. The results are beneficial for designing the lead time and the frequency of warning or intervention in rear-end collision alarm systems.