Non-Vital Advance Rail Preemption of Signalized Intersections Near Highway-Rail Grade Crossings

This project summary report summarizes the research performed in Texas Department of Transportation (TxDOT) Project 0-4746. In this three-year project, researchers developed and tested two alternative strategies for ensuring safe pedestrian clearance at highway-rail grade crossings. The strategies were called Non-vital Advance Preemption (NVAP). Both strategies were tested in TTI's TransLink laboratory using hardware-in-the-loop simulation and in the field at a test intersection in College Station, Texas. This research showed that TxDOT could potentially enhance pedestrian safety by using non-vital advance preemption. Non-vital advance preemption strategies use existing functionality of current traffic signal detectors to safely provide track clearance without needing shortened pedestrian walk or clearance intervals; however, these strategies require accurate estimates of train arrival times at grade crossings. To achieve the necessary accuracy, TxDOT should not rely solely on monitoring the preemptions from upstream intersections, but deploy active devices to measure train speeds and movements directly in a rail corridor. Using these devices, TxDOT can minimize the arrival time estimation problems observed in this project.