It's similar to using a hammer on a pushpin. Venglar is heading up an effort to develop a new method for signal controller treatment of railroad preemption based on advanced train detection. Existing preemption standards allow traffic signal controllers to cut short pedestrian and vehicle phases that conflict with the track clearance phase. Venglar says that this can lead to problems for vehicles and pedestrians. The problem for motorists is how to proceed with a shortened light sequence.
Shortened sequences can cause confusion and hesitation on the part of drivers.
The TPS algorithm relies on advanced train detection technology to offer at least one full minute of advanced warning. TPS is being designed to work in conjunction with current preemption practices. Venglar says the idea is to present a solution that augments the current system. TPS will provide a smoother transition into the preemption sequence by adjusting the timing of each intersection phase as needed. Pedestrians, for example, are either given enough time to safely cross, or they are signaled not to cross until the preemption sequence has finished.