MODEL TO EVALUATE THE IMPACTS OF BUS PRIORITY ON SIGNALIZED INTERSECTIONS

Transit service is being viewed increasingly as a reliable travel demand measure. Various means of attracting the motorist to move from the car to transit are being attempted all over the country. It has been found that delay at intersections is the primary cause of bus delay. Reducing delay at intersections can reduce overall trip time, improve schedule reliability, and reduce overall congestion. Providing priority for buses at signalized intersections is one way to reduce delay at intersections. Numerous organizations have developed priority strategies to do the same. But most of them cannot be operational for a long time for various reasons. Improved technology has prompted traffic engineers to renew efforts to develop newer bus priority strategies. This paper discusses the development of a model to evaluate the impacts of implementing a priority strategy at signalized intersections. The model uses the delay equation for signalized intersections in the 1985 Highway Capacity Manual. A priority strategy was developed and implemented in the field. Data were collected, and delay in the field was measured. The model seems to be predicting delay reasonably accurately. In some cases, however, the model was overestimating delay. The model can be a useful tool to traffic engineers to evaluate the impacts and the feasibility of implementing a priority strategy.