Using Hardware-in-the-Loop Simulation to Evaluate Signal Control Strategies for Transit Signal Priority

Document Type

Journal Article

Publication Date


Subject Area

operations - coordination, operations - traffic, infrastructure - stop, infrastructure - bus/tram priority, infrastructure - bus/tram priority, infrastructure - traffic signals, ridership - commuting, mode - bus, mode - subway/metro, mode - bike


TriMet (Portland, Oregon), Tri-County Metropolitan Transportation District of Oregon, Transit signal priority, Traffic signal networks, Traffic signal coordination, Traffic signal control systems, Synchronization (Traffic signals), Spreadsheets, Portland (Oregon), Performance, Nearside (Bus stops), Linked signals, Interconnection (Traffic signals), HIL simulation, Hardware in the loop simulation, Green interval (Traffic signal cycle), Farside (Bus stops), Deterministic models, Computer controlled signals, Bus priority, Automatic traffic signal control


The City of Portland, in collaboration with TriMet (Portland’s regional transit service provider) and the Oregon Department of Transportation, has implemented transit signal priority (TSP) at more than 240 intersections on seven transit routes as a part of the Streamline program. This study focuses on the simulation of one intersection in Portland by using hardware-in-the-loop simulation to examine the effects of TSP signal control strategies on transit performance. More specifically, near- and farside bus stops are studied with hardware-in-the-loop traffic simulation to determine the effect of stop location on the effectiveness of the Portland TSP system. This analysis is verified by using a deterministic spreadsheet model to determine the effectiveness of the system and to address whether a green time extension plan should be used if there is passenger activity at a nearside stop.