Effects of Traffic Control Device and Hazard Location on Fixations During Intersection Navigation: A Simulator Study

Collisions resulting in injuries or fatalities occur more frequently at intersections. This is partly because safe navigation of intersections requires drivers to accurately observe and respond to other road users with conflicting paths. Previous studies have raised questions about how traffic control devices and the positioning of other road users might affect drivers' visual search strategies when navigating intersections.To address these questions, four left-turn-across-path (LTAP) scenarios were created by combining two types of traffic control devices (stop signs and traffic lights) with two hazard starting locations (central and peripheral). Seventy-four licensed drivers responded to all scenarios in a counterbalanced order using a full vehicle driving simulator. Eye-tracking glasses were used to monitor eye movements, both before and after hazard onset.The results revealed that drivers at the signalized intersections took longer to fixate the LTAP hazard before onset, spent less time fixated on the hazard, and made fewer visits to the hazard compared to drivers at the unsignalized, stop-sign controlled intersections. There were no significant main effects of hazard location on the eye tracking measures, however, there was an interaction between the traffic control device and the hazard location on total fixation duration. Participants fixated the signal-controlled hazards longer in the central location but fixated the stop-sign controlled hazards longer in the peripheral location.Despite the inherent risks of intersecting traffic, results indicate the drivers at signalized intersections rely heavily on the traffic control device to prevent collisions. Given the high speed and traffic volume at signalized intersections, these results can be used to justify the implementation of measures such as protected left turn signals and other infrastructure changes aimed at reducing the frequency and severity of LTAP collisions.