Capacity And Optimization Strategy Of Diversion Area For Mixed Traffic Flow

The diversion area is one of the important nodes of the road network.The traffic operation status of the diversion area is relatively complex,the traffic flow is in disorder,and the service level of the road is relatively low,greatly limiting the function of the road network.How to improve the traffic capacity of the diversion area and improve the order of traffic flow is one of the important contents of traffic flow research.With the rapid improvement of technology,the emerging technology of connected autonomous vehicles has created new opportunities for the development of active traffic management strategies.It is expected that in the next twenty years or even longer,autonomous vehicles will gradually be put into use,forming a mixed traffic flow environment of autonomous vehicles and human driving vehicles.Therefore,facing the future mixed traffic flow environment,further exploring the traffic capacity of the diversion area is of great significance for the research and development of future vehicles and roads.In addition,with the gradual maturity of the development of autonomous driving and vehicle networking technology,it is possible to improve the traffic efficiency of the diversion area and reduce vehicle driving delays through systematic strategic control.Firstly,this paper studies the theory of expressway diversion area,laying a theoretical foundation for analyzing the traffic operation characteristics in the diversion affected areas.Based on the public vehicle trajectory data set of Yingtian Avenue from the UTE team of Southeast University,the traffic flow operation characteristics in the diversion area were statistically analyzed,and the operation conditions of each lane in the diversion area were visually analyzed using the vehicle flow trajectory space-time map.The lane changing behavior and characteristics of vehicles in the diversion area were further studied.Finally,based on the previous qualitative and quantitative analysis,summarize and analyze the impact factors of traffic operation in the diversion area under human driving conditions at this stage,providing a theoretical basis for the following research on traffic capacity in the diversion area and formulating reasonable road traffic control strategies.Secondly,this paper uses the updated Waymo-Open-Data open autopilot dataset,and completes the original data analysis,scene selection,trajectory data coordinate conversion,trajectory data inspection and smoothing.Genetic algorithms are used to calibrate the IDM car following model parameters of networked autonomous vehicles and human driving,making the simulation conclusions more convincing.Then,based on the conclusions of the aforementioned analysis of the impact factors on the diversion area,market penetration,diversion ratio,number of off-ramp lanes,vehicle speed restrictions,deceleration lane length,and lane change behavior are selected as the main relevant factors that affect the traffic capacity of the diversion area.Using a car-following model calibrated using open data sets,simulation analysis is conducted using the SUMO simulation platform to analyze the impact of different factors on the traffic capacity of the diversion area.The simulation results provide simulation data support for formulating reasonable road traffic control strategies to improve traffic efficiency in the diversion area.Finally,this paper proposes three upstream control strategies for connected autonomous vehicles in a mixed traffic flow environment in an existing diversion area,and explores the strategic control of the number of lane changes and the spatial distribution of lane changes in the diversion area.SUMO simulation results show that improving the market penetration of connected autonomous vehicles and implementing upstream control strategies can improve traffic efficiency and reduce average travel delays in the diversion area.In addition,this paper proposes suggestions for the optimization of the physical geometry of the diversion area from three aspects: the form of the diversion area,the length of the deceleration lane,and the number of off-ramp lanes,in combination with the characteristics of mixed traffic flow,for planning or future construction of roads.