Active and Passive Bus Priority Strategies in Mixed Traffic Arterials Controlled by SCOOT Adaptive Signal System

Abstract

In recent years, bus priority techniques for signals controlled by traffic management centers have become a viable alternative to reduce passenger delays at signalized intersections, especially in mixed traffic corridors. However, before any bus signal priority strategy is deployed in such corridors, the impacts on the different users of the system should be evaluated. The main objective of this work was to assess the operational performance of passive and active bus priority techniques in fixed and real-time signal systems of one of the main arterial corridors in Fortaleza, Brazil. As a secondary objective, it also evaluated the operational benefits of a SCOOT adaptive signal control system, comparing it with well-adjusted fixed-time plans optimized by TRANSYT, for periods of medium and high traffic volumes. In the evaluation of alternative scenarios, the following performance measures were considered: vehicle delay and number of stops simulated by SCOOT, as well as bus and automobile travel times observed in the field during the operation of each scenario. The results did not favor the adoption of passive and active priority schemes in the studied corridor; this led to the conclusion that SCOOT's real-time control, programmed for a good signal progression of the general traffic (buses and automobiles), is the best signal control strategy for an arterial corridor similar to the one under analysis.