| With the development of social economy in our country,the number of cars keeps increasing.However,the urban road resources in our country are limited,which results in the problem of traffic congestion and environmental pollution and resource consumption,focus on the development of urban pub lic transport can effectively ease traffic congestion.Because of the low energy consumption and emission,large capacity reserve,fast running speed,strong terrain adaptability and less investment cost,the modern tram has been paid more and more attention.Many cities in our country have already opened the operation of modern trams and more cities will be opened to operate modern tram.Intersection is the bottleneck to solve the problem of traffic congestion,how to realize the priority of modern tram and to ensure the overall benefits of the intersection at the same time is a problem worthy of further study.In this paper,use the method of system analysis to analyze the three types of time priority control strategy,analyze the three measures of relative priority control strategy,shows the schematic diagram and logic flow chart of each measure.After extending the priority phase green time and the priority phase of the red light ahead of the end,using the Webster graphical method to calculate the delay of the preferential phase reduction and the increase of the non priority phase so as to get the whole intersection delay variation.According to the change of intersection delay,this paper gives the signal priority control flow.Establish the optimal model of signal priority time based on the average delay of vehicle.Establish the optimization model of the periodic time of signal intersection based on the delay per person,show the formula for calculating the time of yellow light and the interval of green light.After the priority control is implemented in the current cycle,the corresponding green time compensation can be made in the following cycle.According to the signal timing parameter optimization model established in this paper,the parameters are calculated,and the program is compiled by using the VisVAP module in the micro simulation software VISSIM.Compare and analyze the simulation results of the fixed time control strategy,the conventional actuated control strategy and the signal priority control method proposed in this paper,and the results show that the priority control method proposed in this paper can effectively reduce the intersection delay and give full priority to the modern tram. |
