Study On Optimized Coordination Of The Highway Exit Toll Station And Connected Intersection

Connection of highway and common road mainly includes the upstream toll station,connecting sections and the downstream intersection,which becomes the important link connected to the highway and common road.Subjected to the traffic level and means of traffic control,peak traffic flow brings great pressure to both highway and road network.Although increasing the capacity of the toll station may reduce the queuing pressure of the toll plaza,the large amount of traffic flow will brings pressure on the downstream intersection.On the other hand,to improve the adjustment of the intersection,it is commonly used to optimize the signal timing scheme can alleviate the traffic pressure of highway exit section.However,extending the green time of the phase will also increase the delay time of other imported traffic,reducing the overall level of the intersection.Therefore,to match the capacity of the upstream toll station and the downstream intersection to evacuate the traffic flow in timely,coordinated controlling is beneficial to evacuate the traffic flow in the connect section,which can ensure the smooth operation of highway and common road.In this paper,it is mainly studied that coordinated optimization of the upstream toll station and downstream intersection,with considering of the releasing condition of upstream and downstream at the same time.Firstly,we can master the traffic flow changes through the analysis of the highway toll data.According to these data,time series with traffic flow value can be segmented,which can decrease the interval fluctuation.Secondly,based on the analysis of the traffic flow characteristic of the connecting section and considered the maximum queuing length constraint and the fluctuation range of the flow,it is established an optimized model to realize the maximization of overall benefit of traffic of connecting section.Then,by introducing the penalty function,the optimal upstream releasing flow and the downstream optimal signal timing scheme can be obtained by using the genetic algorithm,which can provide reference for coordinating and optimizing the connecting section traffic.Thirdly,we take Dalang toll station as an example,compare the optimal timing scheme which is obtained by the optimized model with the current timing scheme as well as Webster timing scheme by using the VISSIM simulation technology.The result shows that the optimal timing scheme can ensure that the maximum queue length is less than threshold and can reduce the average delay level of the whole intersection at the same time.Finally,it is suggested that convergence optimization model can be obtained for different optimization objects for different traffic levels and different variables,which can provide the basis for the development of measures of engineering,optimized control and traffic management.