Previously researched path intrusion scenarios include left-turning hazard vehicles which intrude laterally across the path of the through driver. A right turning vehicle, however, creates a scenario where a hazard which was initially travelling perpendicular to the driver can intrude into the through driver’s path without also occupying the adjacent through lanes. This hazard scenario has not been previously investigated. The purpose of this research was to determine driver response time (DRT) and response choice to a right turning vehicle that merges abruptly into the lane of the oncoming through driver.
Using an Oktal full car driving simulator, 107 licenced drivers (NFemale = 57, NMale = 50) completed a five-minute practice drive followed by a ten-minute experimental drive containing two conditions of the right turn hazard, presented in a counterbalanced order. In one condition, the hazard vehicle was stopped with its front bumper at the stop bar before accelerating into the path of the participant driver. In the other condition, the hazard vehicle approached the intersection and turned at a constant speed. DRT was defined as the time between when the hazard vehicle crossed the stop bar and when the participant driver reacted by touching the brake pedal or swerving.
There was a significant difference in DRT (p < 0.001) between the two hazard conditions with drivers responding earlier to the right turning vehicle when it was initially in motion. In both scenarios, approximately half of the through drivers swerved in response to the hazard vehicle. Participants who chose to swerve were slower on average, although this response type did not result in significantly more collisions (χ2(2) = 2.02, p = 0.14).
