OTREC-RR-13-07

The Sydney Coordinated Adaptive Traffic System (SCATS) is used to mitigate urban traffic congestion. This research combines SCATS research areas including: a) the relationship between SCATS, traffic volumes, and Transit Signal Priority (TSP); b) between TSP and traffic conditions; and c) the correlation between signal timing and air quality. SCATS showed significant speed improvement at a minor intersection, though major intersection results were mixed. Non-priority signals had a greater impact on travel time than priority signals. A regression model of intersection delays showed major intersections with high cross-street volumes are not likely to experience TSP benefits. Signal timing and queuing have a high impact on pedestrian exposure. Longer green times along the main corridor significantly reduced particulate matter, whereas longer street crossing time increased queuing and exposure. Reduced bus idling time and proper bus shelter orientation are likely to reduce pollution exposure significantly.