Next-Generation Transit Signal Priority with Advanced Arrival Time Prediction and Custom Traffic Signal Control Logic
Document Type
Journal Article
Publication Date
2025
Subject Area
place - north america, place - urban, mode - bus, infrastructure - bus/tram priority, infrastructure - traffic signals, operations - reliability, technology - automatic vehicle monitoring
Keywords
traffic signal systems, intersection performance, multimodal, signal priority, public transportation, bus transit systems
Abstract
Transit signal priority (TSP) is a signal timing strategy to give priority to transit by adjusting the signal operation with the goal of reducing transit delay and improving reliability. While TSP can be a powerful tool, TSP deployments in the U.S. have often resulted in marginal improvements. The primary reasons for limited TSP effectiveness are short detection horizons for TSP requests (e.g., 10 s), near-side bus stops (i.e., located before crossing an intersection) that influence arrival times at the downstream traffic signal, and restrictive signal timing strategies (e.g., lock-out policies that inhibit TSP for a specified amount of time, coordinated control that offers little flexibility for TSP). This paper documents the impacts of a “next-generation” TSP system that couples with custom signal control logic for TSP through a field deployment in Portland, Oregon, U.S., using emerging data sources. The system uses cloud-based, predictive logic for estimating time of arrival, with predictions of bus arrivals available up to 2 min ahead of each intersection and updated continuously every 1 s. The custom signal control logic includes advanced TSP strategies that can take advantage of early prediction. Using data from high-resolution automatic vehicle location, analysis results show the custom signal controller logic with advanced prediction resulted in an average bus delay reduction of 29 s per intersection at major intersections (a reduction of 69% compared with baseline). Analyses using automated traffic signal performance measures and vehicle probe data showed these bus delay improvements were achieved with marginal impacts on motorists and without additional delay to pedestrians and bicycles.
Rights
Permission to publish the abstract has been given by SAGE, copyright remains with them.
Recommended Citation
Cesme, B., Barrios, J. A., Koonce, P., Haines, M., Furth, P., Bame, C., & Dobrota, N. (2025). Next-generation transit signal priority with advanced arrival time prediction and custom traffic signal control logic. Transportation Research Record, 2679(9), 308-323.
