Vehicle Lane Changing Behavior In Urban Expressway Merge Area

In order to meet the increasing long-distance travel needs of residents and alleviate traffic congestion in cities,many large and medium-sized cities are actively constructing expressways as an important support for the city's main road network to achieve rapid operation of urban road traffic.The expressway merge area,as a key node of the interaction between the main road traffic and the ramp or auxiliary road traffic,affects the efficiency of the entire expressway.The lane-changing behavior of vehicles entering the main road from the ramp or the auxiliary road will cause interference to the traffic flow on the main road.Therefore,it is necessary to study the lane-changing behavior of vehicles on the merge of expressway.Firstly,three different types of confluence areas(including upstream road sections,merge sections and downstream road sections)of Fuzhou Sanhuan Expressway are selected,namely the construction of the new ramp-main road merge area(hereinafter referred to as "ramp merge area"),Pushang auxiliary-main road merge area(hereinafter referred to as "auxiliary road merge area")and the Wanbian combined merge area(combined by the ramp merge area and the auxiliary road merge area)are the research objects;the upstream road section(200m)and the merge section(250m)and the downstream section(200m)are the research area;the peak time and the flat peak time are the research time.The drone is used for high-altitude hovering to capture the traffic flow under natural driving conditions,and the Tracker video processing software is used to obtain traffic flow data and vehicle driving trajectories.Secondly,according to each traffic flow data,using correlation analysis,model selection analysis and other methods,the traffic volume,driving speed,and headway distance are plotted respectively with the driving direction of the vehicle;the traffic volume and traffic composition characteristics are analyzed;The flat peak law of vehicle travel speed and the travel speed characteristics of each confluence area are studied;the headway time characteristics of different lanes and different sections under different time periods are studied;a three-dimensional model of section position-traveling speed-headway distance is es Tab.lished.Thirdly,according to the driving trajectory maps of the vehicles on the lanes of the upstream section,the merging section and the downstream section at different time periods,the trajectory characteristics of the vehicle lane change are obtained;at the same time,the distribution of the starting point of the vehicle lane change is counted,and the lateral delay diffusion characteristics of the vehicle lane change of the three lanes of the acceleration lane and the main road are obtained by using the heat exchange diagram of the lane change frequency.Finally,according to the trajectory curve of the vehicle in the natural driving state,the genetic algorithm module in Matlab is used to es Tab.lish the vehicle lane-changing behavior model,and the accident-prone road signs are set based on the model.