METHODOLOGY FOR EVALUATING BUS-ACTUATED, SIGNAL-PREEMPTION SYSTEMS

The objective of this research was to model the impact of bus-actuated, signal-preemption systems on delay experienced by buses at signalized intersections and to develop a methodology to evaluate these systems by location. The model developed is green-extension strategy that quantifies the effect of the system on bus and other traffic at intersections depending on the characteristics of the intersections. Based on random arrivals, equations quantify the travel-time savings and losses experienced. Then, the cost of the preemption system is developed, and a revenue-cost ratio for any location is developed. The application of this revenue-cost methodology to a local bus route resulted in a 14:1 revenue-cost ratio. Transportation planners who reviewed this result and methodology expressed the desire to emphasize the ability of this system to reduce bus running times enough to remove at least one bus from the route. This criterion was applied and a bus was removed in the test corridor. Another result of this review was the initiation of field checks to test the assumption of random bus arrivals. Although these checks are not complete, the preliminary results suggest that under most circumstances the random-bus-arrival assumption is valid. Furthermore, in the cases that are being identified by these field checks as not having a uniform distribution, the distribution may either lessen or enhance the feasibility of a signal-preemption installation. From these results we concluded that the methodology and the priority technique are both sound. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 11-17
  • Monograph Title: Evaluation of transportation operational improvements
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00170558
  • Record Type: Publication
  • ISBN: 0309026555
  • Files: TRIS, TRB
  • Created Date: Apr 12 1978 12:00AM