Lane Specific Dilemma Zone Warnings at Signalized Intersections

Abstract

AdministrationThis simulator experiment compares driver behavior in the Dilemma Zone (DZ) on a 4-lane divided highway using three types of warnings of impending traffic signal end of green to no advance warning (control). The DZ occurs when onset of a yellow signal occurs at a temporal interval before an intersection such that stopping or proceeding through the intersection has roughly equal perceived risk. Two of the systems allowed lane specific warnings and one did not. Sixty-nine participants drove a total of 45 minutes in the right lane of on a multilane highway with 36 intersections. On approach to 10 of the intersections, participants were placed in the DZ. For 6 other intersections drivers (still in the right lane) were exposed to a warning not intended for them but for a driver behind them in the left lane. Participants in all warning conditions received warnings 1.5 s or 3.0 s in advance of the end of green. Drivers in all of the advanced warning conditions stopped at the DZ intersections significantly more often than control condition drivers. When stopping at intersections, drivers given an advanced warning decelerated more gradually than those that had no warning. One exception was when drivers misinterpreted the left lane warning as intended for them and therefore decelerated rapidly to stop at the intersection.