Study On Improved Methods Of Signal Control Based On Bus Priority At Isolated Intersection

With the development of socio-economic and urban modernization, the disparity between supply and demand of urban traffic is growing. In this case, the public traffic became the preferred travel mode choice in urban transport because of irreplaceable advantages. And public traffic with its large capacity, high efficiency became the key of urban transport development. But the current situation of public transport development is not very satisfactory, because of low speed, low punctuality, irrational bus lines and so on, the attractiveness of public traffic is very low. Therefore, improving the bus service is the first things in development of public transport priority.In order to reduce congestion to improve bus transit service levels, this paper studies bus priority strategy from traffic signal control. In the paper, bus priority included two parts:single-vehicle bus priority applications and multi-vehicle bus priority application, and the studies of single-vehicle bus priority applications is the base of studying multi-vehicle bus priority application. In the case of single-vehicle bus priority applications, this paper analyzes change of delay and the number of vehicle stopped in each phase of the intersection after using green time extension and early green strategies. And on this basis, it built the comprehensive benefit assessment model with the target of the total delay of the people and the number of vehicle stopped. And then it gets the parameters of the signal-timing by using this model. And the control system achieves its goal of bus priority when the intersection is running at maximum efficiency. In the case multi-vehicle bus priority applications, the system needs to get the sequence of responding to bus priority. This paper combined the approach of conflict Identification with approach of the decision tree reasonably, and it choose the best sequence of responding to bus priority with the optimization target of average total delay per person of bus. This paper gives examples to demonstrate that the above approach is effectual and feasible.