An-Najah Staff

In the last decade, the world experienced a renewed interest in using the advanced technology to improve transit service operation, reliability, and image. The development of the Intelligent Transportation Systems (ITS) in the last decade contributed towards this renewed interest in transit services. Providing preferential treatments for high occupancy vehicles (HOV) will make the HOV more competitive with other modes of transportation. This will increase the transit modal split and reduce single occupancy vehicle demand, thus reducing traffic congestion within the urban boundaries.
The study examined various bus priority signal (BPS) strategies for a major corridor in the City of Ann Arbor, Michigan, USA. The BPS process was simulated using TRAF-NETSIM software. The graphic animation feature in the software was used to monitor the bus arrival at the signalized intersection.
The preemption plans of green extension/red truncation with/without compensation, the skip phase, and the conditional preemption were evaluated. The most appropriate preemption plan for each intersection along the study corridor was determined.
The vehicular (vehicles, buses, and carpools) measures of effectiveness (MOE) in terms of travel time and delay were tested under various levels of network traffic volumes and main to cross street traffic ratios for an isolated intersection. The signal priority for carpools was also tested.
The general conclusion that traffic progression is most critical under heavy traffic conditions. Traffic volume guidelines for signal preemption strategies were also established. The study concluded that there are advantages of providing a limited percentage of carpools with the signal preemption capability.