The Simulated Study On Effects Of BRT Signal Priority In The Intersection

The BRT signal priority can raise the speed of BRT in the intersection. The save time of BRT is very limited without signal priority in the intersection, even there are BRT special lanes. But, the whole traffic situation will change with the BRT signal priority. So, it is very important to study the effects of BRT signal priority in the intersection.There are two fundamental BRT active signal priority strategies (early green and extended green). We have studied the effects of BRT signal priority in the intersection through traffic simulation. The mainly aspects including are as follows.(1) Review the research of the BRT signal priority strategies at home and abroad, and analyze the BRT signal priority of early green and extended green deeply. The traffic simulation model is based on the cellular automata.(2) Establish the relatively independence and effective criterions of BRT in the intersection through analyzing the relationship of the evaluating criterions at intersection, and focuses on the realization of the simulation methods. The criterions system includes traffic flow and traffic running. The traffic flow criterions include vehicle density, average speed and traffic flow. The traffic running criterions include average delay, average queue length and average parking frequency.(3) Simulate the signal of the Heyinongchang stop on the No.1 of BRT in Beijing based on the survey data. Firstly, fix the parameters of the simulation model. Secondly, simulate the BRT signal priority strategies from three situations. They are early green, extended green and both .Finally, analyze the different impacts and get the conclusions.The next study will be more deeply including BRT signal system control in the intersection, the effects of BRT stops and signal distribution patterns based on the cellular automata.