Boundary Control Timing Decision Method For Multiple MFD Sub-regions

During the process of urbanization,the rapid increase of vehicle ownership has resulted in the continuous increase of traffic demand,which not only aggravated traffic congestion,but also increased the difficulty of traffic management and control.However,traffic congestion is one of the important factors that seriously restrict the urban development.Therefore,improving and alleviating urban traffic congestion has become the most difficult problem to accelerate urban development.Traffic congestion and its subsequent evolution of complex and diverse urban road networks will eventually become regional congestion or large-scale congestion.However,traditional control model method is difficult to get accurate OD data from traffic,resulting in traffic control and difficult to meet residents’ travel needs.Although the macroscopic fundamental diagram has confirmed that provides a good platform for the overall judgment of network traffic state and control,but because of the difference in the traffic state of the road network sub-regions,how to effectively implement the boundary control method is the key to solve the traffic congestion in the macro road network.This paper relies on the National Natural Science Fund Project ―network traffic detection based on the temporal and spatial feature extraction and algorithm of rapid evacuation(No.61304195)‖ and Anhui Province Natural Science Fundation Project ―space traffic network situation conversion mechanism and rapid evacuation study(No.1408085QF111)‖,this paper proposes a method of boundary control timing decision for multiple MFD sub-regions.The main research includes the following aspects:First,by comparing the conventional traffic volume prediction method and considering the characteristics of the macro road network,a regional traffic network macro traffic prediction method is established by using the dynamic Lagrange factor,combined with the prediction of Kalman filtering and the change rule of macroscopic traffic volume.Secondly,the sub-regions of the road network are divided according to the characteristics of MFD,and then the evaluation indexes of the fixed detection data and the floating car data are divided,comprehensive consideration of links and intersections,traffic demand and other factors,put forward the model of regional road network traffic state identification.Thirdly,the traffic flow balance equation of the road network sub-regions is established according to the traffic flow conversion relation of the road network sub region and the MFD theory.Taking the minimum risk of congestion on the whole road network condition as the goal and satisfying the minimum vehicle completion rate and the total travel time as well,the traffic condition can be changed by adjusting the border control rate.Finally,a case study is carried out based on the actual road network.By comparing the boundary control method with timing decision and control method without timing decision and other control methods,the results show that the boundary control method with timing decision can not only improve the efficiency of road network,but also alleviate congestion and traffic state transfer effectively,and reduce the risk of traffic congestion.