Research On Signal Priority Control Method For Tramway Intersection In Medium And Small Cities

Trams are one of the most effective measures for the development strategy of " public transit priority ",which can significantly improve the current situation of bus operation in small and medium-sized cities,realize the redistribution of right of way,and optimize the traffic structure of small and medium-sized cities.However,because the selection of control strategy of tram intersections in small and medium-sized cities relies too much on engineering experience or only takes a single intersection as the optimization target,there is a dispute on the right of way between social vehicles and trams.Based on this,this paper has carried out the following aspects of research.On the basis of defining the scope of small and medium-sized cities and summarizing the evolution process of small and medium-sized cities,this paper makes a comparative analysis from three aspects of road system characteristics,traffic mode characteristics and residents' travel characteristics of small and medium-sized cities.In order to solve the problem of choosing the traffic control strategy of the streetcar intersection,this paper analyzes the selection of the signal control strategy of the streetcar intersection in the urban road network from the point of view of the road network system,based on the theory of two-layer programming model.Network of tram intersection signal control strategy choice and traveler travel route choice abstracted as a two-layer model,the upper model with minimum travel time in the whole society as the goal,the lower model for social vehicles and passenger flow modeling tram,accordingly on the optimized road network traffic distribution,the distribution result feedback to the upper model,get the set of intersection signal control strategy.The model is solved by genetic algorithm,and the specific process is given.According to the results of intersection control strategy selection,different priority types of streetcars arriving at intersections at different times are given based on timetables,and the priority logic flow chart of streetcar signals at intersections is given.The phase design and signal control parameters of streetcar intersections are analyzed.The optimal model of intersection signal timing is established by taking the delay per capita as the objective function.The model is applied to some road networks in wenshan city,yunnan province,and the results show that applying the two-layer programming model to the study of the organization design of tram traffic can improve the overall operation efficiency of the road network and reduce the total travel time of the whole society in the system.The feasibility and applicability of bilevel programming model in solving such problems are verified.Finally,taking the intersection of kaihua middle road and puyang west road of the streetcar line 1 in wenshan city,yunnan province as an example,the case calculation was carried out,and the model was verified by simulation with VISSIM software.The results show that the delay per capita is significantly reduced after adopting the signal timing optimization model.