Study Of Neighbor Weaving Sections Carrying Capacity Based On Self Organized Criticality

Weaving area is an area where two or more traffic flows are moving in the same direction without traffic control.The traffic flow in this area will not only change with time,but also be affected by spatial factors.With the continuous input and output of vehicles in multiple adjacent weaving areas,the weaving area will reach a critical congestion state.If it continues to develop,it will cause node congestion,even spread to the whole adjacent weaving area.Therefore,before reaching the critical congestion state,it needs to be disturbed to make it return to the self-organized critical state.The number of vehicles carried in this critical congestion state is the best carrying capacity for the effective utilization of the adjacent weaving area.Defining the number of vehicles in the adjacent weaving area under this kind of operation quality can maintain the stable development of the system and ensure the overall operation quality of the adjacent weaving area.Since the carrying capacity of adjacent weaving area can be used as the standard for traffic management departments to provide control and guidance measures for road network,it is of great practical significance to study the carrying capacity of adjacent weaving area by using self-organizing critical theory combined with the operation characteristics of adjacent weaving area.Firstly,the structure of adjacent weaving area is analyzed,and the propagation process of self-organization is analyzed by using traffic wave theory.It is found that the occurrence of traffic congestion is related to the amount of traffic that adjacent weaving area can accommodate.According to the two-dimensional evolution process of adjacent weaving area,the traffic phases of adjacent weaving area are divided into smooth phase,transition phase and congestion phase,The verification method of the self-organized criticality of the adjacent weaving area is designed,and the self-organized criticality of the adjacent weaving area of Renhe interchange is verified.Secondly,according to the self-organized critical characteristics of the adjacent weaving area,the concept and related models of the bearing capacity of the adjacent weaving area are clarified.By analyzing the internal and external disturbance modes,the influencing factors of the bearing capacity of the adjacent weaving area are explored,and the coupling analysis and spatiotemporal dissipation analysis of the influencing factors are carried out.Thirdly,by establishing a three-dimensional traffic flow self-organization model of the adjacent weaving area,a self-organization critical threshold method of the adjacent weaving area is proposed.This method selects the cusp catastrophe theory of the self-organization theory and integrates the Gaussian mixture model.By determining the upper and lower thresholds of vehicle speed,time occupancy and traffic volume in different states,the threshold value of the adjacent weaving area is calculated,To judge the traffic state of each partition unit in the adjacent weaving area;According to the relationship between each interleaver and the system,the state classification threshold of the adjacent interleaver is set,and the critical point of the adjacent interleaver before congestion is defined as the self-organized critical state of the adjacent interleaver;Then,through the operation mechanism of traffic state changing with time,the self-organized critical state threshold calculation model of adjacent weaving area is constructed.According to the structure and operation characteristics of adjacent weaving area,the relationship between traffic volume change and occupancy is extended from a single weaving area to the whole adjacent weaving area.By calculating the occupancy of adjacent weaving area at different times,and considering the lane length of adjacent weaving area division unit and the corresponding occupancy change,the calculation model of bearing capacity of adjacent weaving area is constructed.Finally,taking Renhe interchange in Chongqing as an example,this paper makes an empirical study on the adjacent weaving area.According to the survey data of each entrance and section of the adjacent weaving area,this paper analyzes the vehicle operation characteristics of the adjacent weaving area,and calculates the self-organized critical state threshold of each weaving area.Then,the VISSIM simulation software is used to simulate the traffic flow situation of the adjacent weaving area before and after induction,and the traffic flow difference and carrying capacity of the simulation results are calculated The results are analyzed.Finally,by comparing the traditional space-time dissipation method with the proposed method,the differences and advantages between the proposed method and the traditional space-time dissipation method are obtained,and it is shown that the uniform distribution of vehicles in the weaving section can improve the bearing capacity of the adjacent weaving section.