Bus Signal Priority Method At Arterial Signal Progression

With the increasement of vehicle quantities and intensifies of urbanization, traffic congestion problem is getting worse. Giving priority to urban public transportation is a good way to improve traffic resource utilization and ease traffic congestion. As a signal timing optimization technique which considering bus interests, bus priority signal control play an important part at improving public transport services and public transport system's interests. In urban traffic signal control, arterial signal progression is usually used to ensure the traffic flow smoothed running. And the offset and green wave band is accounted by the main social traffic flow. In this condition, green time extended or early start bus priority methods might interrupt signal progression. Therefore, how to incorporate bus priority in the control process without unduly interrupting signal progression is an important question. This paper firstly introduced the relationship of arterial signal progression and bus priority, presents a double-level design, upper and lower limits of coordination phase'green wave were set as restrictions when adjusting parameters, green time extend and early start mode were adopted to achieve bus signal priority under the condition of signal coordination. At last, VISSIM was used to analyze the benefits of control algorithm.Chapter 1 presented topic source and research background, analyzed the necessity of bus signal priority method at arterial signal progression, summarized research situation of bus priority.Chapter 2 studied bus signal priority strategy at arterial signal progression, including layered control strategy, conditional priority strategy, active bus priority strategy, detector setting strategy, green time compensation strategy.Chapter 3 studied bus priority optimization method. At bus delay-based signal priority control, upper and lower limits of coordination phase'green wave were set as restrictions when adjusting parameters, green time extend and early start mode were adopted to achieve bus signal priority under the condition of signal coordination. Calculation methods of key parameter and total flow were established for bus signal priority. Based-on schedules bus signal priority control method is established on the above method, introduced the function of bus, and put intersection delay into green extend and early start module as judgment for green extend or early start. Chapter 4 took RenMin Street as an example to validate the bus signal priority method in Vissim environment.Chapter 5 summarized the research achievements and the next research plan. Research results included bus signal priority method at arterial signal progression and bus weight function.