An Adaptive Transit Signal Priority Strategy Using GPS/AVL and Wireless Communication Systems

This paper reports on a study undertaken to integrate the already-equipped GPS/AVL system on buses with an adaptive signal priority strategy using wireless communications. These communications can consider the bus schedule adherence, number of passengers, vehicle location and speed. The authors describe how the City of Minneapolis recently deployed wireless technology to provide residents, businesses and visitors with wireless broadband access anywhere in the city. They note that traditional presence detection systems, ideally designed for emergency vehicles preemption (EVP), usually send signal priority requests, after a preprogrammed time offset, as soon as transit vehicles were detected, without the consideration of bus readiness. Communication with the roadside controller for signal priority may be established using the readily available 802.11x WLAN (Wireless LAN) or the DSRC (Dedicated Short Range Communication) 802.11p protocol currently under development for wireless access in vehicular environment. The authors describe their proposed priority strategy, its evaluation using microscopic traffic simulation, and the embedded prototype systems. A traffic model of Franklin Avenue in Minneapolis, Minnesota, consisting of 22 signalized intersections, was developed, calibrated, and simulated in order to compare the measures of effectiveness before and after applying the signal priority strategy. Vehicle travel time, delay, speed and number of stops were measured to evaluate the effectiveness of the transit priority strategy. Simulation results indicate that a 12-15% reduction in bus travel time during AM peak hours (7AM-9AM) and 4-11% reduction in PM peak hours (4PM-6PM) could be achieved by providing signal priority for buses.

• Corporate Authors:

  ITS America

  1100 17th Street, NW, 12th Floor
  Washington, DC  United States  20036
• Authors:
  • Liao, Chen-Fu
  • Davis, Gary A
• Conference:
  • 15th World Congress on Intelligent Transport Systems and ITS America's 2008 Annual Meeting
  • Location: New York NY, United States
  • Date: 2008-11-16 to 2008-11-20
• Publication Date: 2008

Language

• English

Media Info

• Media Type: CD-ROM
• Features: Figures; Maps; References;
• Pagination: 12p
• Monograph Title: ITS Connections: Saving Time. Saving Lives

Subject/Index Terms

• TRT Terms: Bus priority; Bus transit; Dedicated short range communications; Dynamic models; Global Positioning System; Peak hour traffic; Public transit; Signalized intersections; Simulation; Traffic signal preemption; Travel time; Wireless communication systems
• Geographic Terms: Minneapolis (Minnesota)
• Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management; Public Transportation; I73: Traffic Control;

Filing Info

• Accession Number: 01137198
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 29 2009 1:53PM