Tram Passive Signal Priority Strategy based on the MAXBAND Model

摘要

This research proposes a new tram progression model, TRAMBAND, which is a passive tram signal priority strategy. TRAMBAND was formulated based on the MAXBAND model, which is a traditional arterial signal optimization model to maximize bandwidth. A tram that leaves a station during an appointed green time can arrive at subsequence station without experiencing intersection delays and stops by using the tram bandwidth. In order to guarantee a desired green time for other road users and minor streets, the TRAMBAND model determines the traffic signal timings for tram passive priority using only a left-turn phase sequence and offset. This strategy also maximizes the general vehicles bandwidth in the context of the fixed tram bandwidth in a median tram rail. The tram dwell-time and its variability influence the efficiency of the passive priority. In this study, the stop time at station is divided by the dwell-time and waiting time. The tram has to wait at station during the waiting time after the dwell-time; however, the waiting time is used as slack time to absorb the dwell-time variability and to maximize the general vehicle bandwidth. The case study is based on nine signalized intersections and a micro-simulator VISSIM, wherein it demonstrates that the proposed tram priority model, TRAMBAND, is capable of computing signal timings so as to avoid intersection delays and stops of tram and maintain the general vehicle bandwidth.