1-4.1: Transit Priority
|Final Report (DOI)
In this research, simulation is used to explore how a bus bypass segment, also called a queue jump, affects traffic on a signalized arterial. Residual queues form at the site’s critical bottleneck and expand to street links upstream. A bypass, when designed to serve a bus stop as per AASHTO guidelines, is shown to reduce bus delays—if the stop resides on a congested link that is upstream of the one feeding traffic to the critical bottleneck. In contrast, using a bypass for a bus stop located immediately upstream of the critical bottleneck starves that bottleneck of flow. The damage thus done to car traffic also penalizes buses operating in the congested lanes that they share with cars. This damaging cross-modal influence can nullify the benefits that buses receive from the bypass segment. The value of a simple alternative, and the generality of the present findings, are verified via parametric tests.