Study On Lane Changing Behavior And Influence Of Vehicles In Urban Continuous Tunnel Weaving Area

As a special section of urban traffic,urban tunnel group has various forms of traffic safety problems,which has aroused widespread concern.Compared with other types of urban expressway weaving area,urban continuous tunnel weaving area has more complex internal vehicle driving,more frequent lane change,more prone to traffic conflict and frequent traffic accidents,which affect the traffic efficiency of vehicles in weaving section.Therefore,this paper studies the car following and lane changing behavior in the weaving area of urban continuous tunnels,and constructs the corresponding model to analyze the impact of lane changing behavior on vehicle traffic in the weaving area,so as to provide a theoretical basis for improving the traffic efficiency and traffic safety in the weaving area.This paper takes the weaving area between “Jiuhuashan Tunnel and Xi’anmen tunnel” as an example.Unmanned aerial vehicle(UAV)is used to photograph the vehicle running process in the weaving area.The vehicle trajectory data is extracted by the A.R.C.I.S system of the intelligent and safe transportation Laboratory of the University of Central Florida.The homography method is applied to modify the data,and the obtained data is smoothed.The feature data required by the model is extracted by Python software.The vehicle braking is divided into reaction braking stage,vehicle braking stage and vehicle continuous braking stage,and the driving distance model of vehicle braking process is constructed.In order to better control the acceleration and deceleration of the front and rear cars,a car following model of acceleration and deceleration of the rear car is constructed.By analyzing the relationship between the acceleration difference and the threshold of left and right lane changing and invariant lane,the demand model of vehicle free lane changing is constructed.This paper analyzes the safety distance between the target vehicle and the front and rear vehicles in the adjacent lane under different conditions,constructs the safety distance model of vehicle free and forced lane change,and introduces the probability model of vehicle forced lane change into the safety distance model of forced lane change.In the simulation environment and parameter setting,according to the theory of cellular automata,the cells of car and road are divided,Poisson distribution function is selected as the random generating function of vehicle,and normal distribution function is selected as the random generating function of vehicle speed.By analyzing the influence of lane changing behavior on upstream and downstream lanes,the influence of lane changing behavior on each lane of main road in weaving area,the relationship between lane changing times and traffic volume,and the relationship between lane changing frequency and traffic flow density,the influence of lane changing behavior on weaving area is discussed.The simulation results show that the outermost lanes of upstream and downstream main roads are most affected by lane change;Lane changing behavior has little effect on the average speed of vehicles in the innermost and outer lanes of the main road,but has a greater impact on the average delay of vehicles;When the traffic volume is small,the timely lane changing behavior can promote the vehicle operation in the weaving area,but with the increase of traffic volume,the number of lane changing will be restrained and reduced;The frequency of free lane change is easily affected by traffic flow density,showing a trend of first rising and then declining,while the frequency of forced lane change does not decrease significantly with the increase of traffic flow density.