Exploring the effects of traffic light countdown displays on the driving behaviours of drivers with different personality dispositions: A VR-simulated study

Abstract

The dilemma zone, where drivers must decide whether to stop or proceed through an intersection as a traffic signal turns yellow, poses a substantial risk for traffic accidents. One factor affecting the dilemma zone is the inconsistency of green light countdown displays across intersections. This VR simulation study aims to investigate how different countdown display settings impact driver behaviour in the dilemma zone. Using a simulated traffic intersection developed using Unity3D, 31 participants completed driving tasks under 5 different green light countdown displays. Vehicle speeds were collected objectively in the experiments. Questionnaires were employed to assess drivers' hesitation levels and personality dispositions. The results from the statistical analysis reveal that drivers with diverse personality dispositions exhibited consistent hesitation levels across countdown displays. While longer countdown displays tended to reduce drivers' hesitation, the countdowns set between 5-10 seconds resulted in lower vehicle speeds through the intersection compared to other shorter or longer settings. This indicates that the optimal green light countdown display for mitigating the dilemma zone is 5-10 seconds. Findings of the study provide useful insights into the relevant research field. Transportation departments may apply these findings to improve driver safety, refine policies, and standardise countdown timers across intersections.