Research On Transit Signal Priority Of Urban Road

With the gradual increase of urban vehicle ownership,especially during morning and evening peak hours,the problem of urban road congestion has become a pain in many cities.Therefore,people think of solving the problem of urban congestion through the development of public transportation,and transit signal priority strategy emerges as the times require.But as more and more buses on the road inevitably encounter the problem of multiple priority conflicts.In order to solve the above problems,this paper establishes a bus signal priority model that considers multiple priority request conflict,and applies the signal priority model to the city arterial.The main work of this paper is summarized as follows:(1)At the signalized intersection,the delay changes of buses and social vehicles with priority phase and non-priority phase are analyzed.The change of multi-signal priority request for bus vehicle passenger delay in the same phase and conflict phase,and the change in the priority phase and non-priority phase of social vehicle passenger delay are analyzed.The overall passenger delay change at the intersection is selected as an indicator to evaluate the priority of different requests,and priority is given to bus signals that can minimize passenger delay at the intersection.The validity of the model is proved by VIS SIM simulation experiments,which can solve the problem of multiple priority requests conflicts and improve the effect of transit signal priority.(2)At the city arterial level,a real-time two-direction green wave model is proposed to ensure the smooth flow of vehicles,and the different situations of up and down teams arriving at the intersection are analyzed,including "head and tail blocked","head and tail passing","head passing tail blocked" and "head blocked tail passing".formulas are calculated for delays caused by different situations.Then,a nested genetic algorithm is proposed.The outer layer aims at minimizing the coordination of external vehicle delays,the inner layer aims at minimizing the coordination of internal delays,and finally obtains the optimal intersection signal timing and phase difference.Simulation experiments with VISSIM prove that real-time two-way green wave coordinated control can effectively reduce vehicle delays on the arterial.(3)A bi-lever optimization model is proposed.The upper layer is a real-time two-direction green wave coordinated control.It can optimize the real-time signal timing according to the traffic volume on the road surface,and minimize the delay at consecutive intersections.The lower layer is a transit signal priority control that considers multiple priority request conflicts.In order for the signal priority control model to meet the coordinated control conditions,the minimum green light time of the coordination phase is added as a constraint condition to prevent the signal priority from causing damage to coordination control.The VISSIM simulation comparison experiment can also prove that on the basis of arterial-based two-direction green wave coordinated control,the problem of multiple priority requests conflict is also solved,and the traffic efficiency of the road is improved.