Queue Jump Lane, Transit Signal Priority, and Stop Location Evaluation of Transit Preferential Treatments Using Microsimulation

Abstract

Transit preferential treatments offer the potential to improve transit travel time and reliability. However, the benefits of these treatments vary greatly depending on the specific characteristics of the study area, including turning movement and pedestrian volumes, signal timing parameters, and transit stop location. To evaluate the performance of preferential treatments, practitioners typically rely on microscopic simulation models, which require a considerable amount of effort, or a review of previous studies, which may reflect a bias toward the area characteristics. This paper develops a test bed and a planning-level framework to help practitioners determine benefits offered by various preferential treatments without developing a detailed simulation model. To evaluate preferential treatment benefits, the authors performed extensive simulation runs under various scenarios at an isolated intersection with VISSIM. The analyses show that the greatest benefit comes from relocating a nearside stop to a farside stop, in which farside stops can reduce delay up to 30 s per intersection. The highest saving that could be obtained with a queue jump lane is approximately 9 s per intersection. As the number of right turns increases along with the number of conflicting pedestrians, the benefit of a queue jump lane disappears. Transit signal priority with 15 s of green extension and red truncation can offer up to 19 s of reduction in delay; the benefits become more pronounced with a high volume-to-capacity (v/c) ratio. With a low v/c ratio, granting 10 s of green extension without red truncation provides very marginal benefits; only a 2-s delay reduction per intersection is gained.