Advance Preempt with Gate-Down Confirmation: Solution for Preempt Trap

Document Type

Journal Article

Publication Date


Subject Area

operations - traffic, infrastructure - bus/tram priority, infrastructure - traffic signals, mode - rail


Traffic signal priority systems, Traffic signal preemption, Railroad grade crossings, Preemption (Traffic signals), Preempt trap, Level crossings, Highway railroad grade crossings, Highway rail intersections, Grade crossings, Grade crossing protection systems, Crossing gates


The preempt trap, a safety issue at some traffic signals near railroad grade crossings with advance preempt, can be addressed in several ways if the operating authority is aware of the potential problem. However, some solutions, such as not using advance preemption, result in other problems, including potentially unsafe clearance intervals during preemption. A simple solution, available from railroads under the standards of the American Railway Engineering and Maintenance-of-Way Association, that provides both safe and efficient operation is evaluated. The evaluation demonstrates the potential value of the use of advance preempt with gate-down confirmation.