Driver Behavior in Left Turn across Path from Opposite Direction Crash and near Crash Events from SHRP2 Naturalistic Driving

The turn-across-path from opposite-direction [LTAP-OD] crash type contributes to one of the major fatal crash types in young drivers. Drivers responses in police reportable and severe crashes and near crashes involving an LTAP-OD scenario were evaluated from query of the Second Strategic Highway Research Program [SHRP-2]. This research examined the responses of through drivers. 122 such events were analyzed to extract driver braking behavior, secondary tasks, age, and perception-response times. All measures of through driver variables were compared with respect to turning driver behavior. The study aimed to identify the trigger event for drivers to respond to the left turning vehicle. Time to contact was a significant factor which affected driver response times. Drivers responded significantly faster when subjected to shorter time to contact events compared to longer ones. Other short time to contact events included when the turning vehicle did not stop before entering the intersection, or when the turning vehicle was visible for a short duration. Driver factors such as age, gender or secondary task engagement did not significantly influence response times.