Assessment of Pre-Preemption Strategy of Traffic Signals near Railroad Grade Crossing Utilizing Simulation Analysis

摘要

The current railroad crossing preemptions consider only safety issues involving train-vehiclecrashes and allow the abbreviation of the vehicular minimum green time and shortening/omittingof the pedestrian “WALK” and flashing “DO NOT WALK” intervals. A few strategies inadvance of the preemption were applied in previous studies to avoid the minimum green timeabbreviations, as well as to improve mobility performance. However, those studies require theinstallation of infrastructure point detectors to predict train arrival and also provide extra greentimes for the non-dwell phases without considering the actual delays. This paper proposes todetect train arrival by utilizing the preemption activations and deactivations at the upstreamintersections along the train’s path. Such a strategy is particularly feasible if a central signalcontrol software can receive the notices of preemption activations and deactivations from thelocal controllers. Based on this type of train detection technology, the feasibility of various prepreemptionstrategies was investigated in this paper using simulation analyses. Four out ofthirteen pre-preemption strategies avoided minimum green time abbreviation in the testedscenarios. The Improved Transition Preemption Strategy (ITPS) was found to perform the bestin terms of reducing average intersection delays.