Research On The Subdivision And Control Method Of Arterial Coordinated Control Based On Spatiotemporal Characteristics

With the rapidly developing society and economy,car ownership continues to rise,and traffic congestion is becoming increasingly serious,affecting residents’ travel experiences.As the main carrier of urban road traffic,urban trunk roads carry most of the travel demand.The implementation of green wave coordination control can improve the efficiency of mainline vehicles,which plays an important role in alleviating traffic congestion problems.To improve the coordination control effect,this paper analyzes and summarizes the existing research,addresses the shortcomings of current research,and conducts research on coordination control methods,coordination control under multi-time period division and subzone division,and coordination optimization methods between adjacent subzones.The main research contents of the paper are as follows:Firstly,the video data of the bayonet are pre-processed to obtain the traffic data for different directions at each intersection.Using mathematical and statistical methods,the spatiotemporal characteristics of urban arterial traffic flow are analyzed from the perspectives of temporal and spatial.Data support is provided for the subsequent proposal of the spatiotemporal subdivision method of urban arterials.Secondly,the spatiotemporal subzone division method based on the spatiotemporal characteristics of traffic flow is proposed.Due to the deficiency that the multi-time period division and subzone division scheme can only adapt to the traffic flow variations in time or space,this paper combines temporal and spatial division methods from the temporal and spatial variability of traffic flow,distribution characteristics,and geometric characteristics of intersections.The recursive ordered clustering algorithm is applied to multi-intersection clustering for temporal division.Based on the temporal subdivision results,the spatial subzone division is carried out by using the correlation degree of adjacent intersections and the number of vehicles passing the intersection without stopping as spatial division indexes,combined with the improved merging index method.The whole arterial is divided into several spatiotemporal subzones to improve the adaptability of the division scheme.On this basis,the spatiotemporal coordination control optimization method for urban arterials is proposed.Based on the results of the spatiotemporal subzone division,the queuing vehicle dissipation time model is established according to the vehicle arrival and departure laws of adjacent intersections.Based on the removal of the constraint of strict symmetry of the green wave band about the centerline,the improved model of MULTIBAND is proposed as the coordination control model within the spatiotemporal subzone.On the premise of satisfying the coordinated vehicle traffic demand between adjacent subzones,the optimal phase difference between adjacent intersections is selected to minimize the delay of coordinated vehicles.For the existence of the non-public cycle coordinated control scheme transition problem,the phase difference adjustment amount of each intersection is calculated by setting virtual cycles.The number of transition cycles is calculated based on the phase difference adjustment amount,and a smooth transition cycle algorithm of up to three cycles is proposed.Finally,the method proposed in this paper is validated by example data and traffic simulation using VISSIM software.The results show that with coordinated control under spatiotemporal subdivision,the overall average queue length,average vehicle delay,and the average number of stops on the arterials are reduced by 13.2%,12.3%,and 9.2%,respectively.Compared with the current timing scheme,the coordinated control scheme under temporal subdivision,and the coordinated control scheme under spatial subdivision,all evaluation indexes of the proposed scheme are reduced,thus demonstrating the practicality and superiority of the proposed method in this paper.The results show that arterial coordination control under spatiotemporal subdivision can alleviate the traffic problems caused by the differences in the spatiotemporal distribution of urban arterial traffic flow,and improve the efficiency of vehicle operation,and also provide new approaches and technical support to urban traffic managers in the formulation of arterial coordination control measures.