Signal Control Optimization Of Expressway Off Ramp And Connecting Ground Intersection Considering Lane Changing Behavior

As the intersection of main line traffic and ground traffic,the off ramp of urban elevated expressway has mixed traffic flow and a large number of lane changing behaviors,which is prone to congestion and is the bottleneck of the expressway network.In the existing intersection capacity analysis related research,the traffic volume as the input parameter is generally obtained by two methods:one is based on the actual traffic survey data,and the other is generated randomly through some statistical law.Neither of these two methods can well consider the micro driving behavior of lane changing.Therefore,this paper takes lane changing behavior and its impact on traffic flow as the starting point to study the traffic control methods in the bottleneck area of Expressway off ramps and connecting ground intersections.Considering that lane changing behavior is a micro behavior with large randomness,which has the characteristics of discretization and dynamics,this paper analyzes it by cellular automata.Firstly,the cellular automata traffic flow model is established by using the cellular automata model;Secondly,the lane changing rules are introduced to establish the lane changing model of cellular automata;Finally,according to the established model,MATLAB software is used for simulation to analyze the correlation between vehicle lane changing behavior and traffic flow.Most urban intersections in China generally adopt the fixed signal control method,which is less flexible and can not be changed in time according to the traffic conditions.The applicability of the intersection facing the exit ramp is poor,which will lead to serious traffic congestion.Therefore,the fixed signal control method is changed to the induction signal control method in this paper.Firstly,the logic control scheme is studied and the corresponding logic control code is written;Secondly,it is realized by VAP control module in VISSIM simulation software;Finally,the induction signal control scheme is obtained.In order to verify the effectiveness of the above lane changing behavior analysis and induction signal control,a case study is carried out.The comparison results of delay data obtained under different conditions show that lane changing behavior will affect the traffic flow efficiency and easily lead to traffic flow failure;Compared with the fixed signal control scheme,after the induction signal control scheme is changed,the average delay,average stopping time and average stopping times of vehicles on the entrance lanes of different aspects of the intersection are significantly improved.Starting from the impact of lane changing behavior on traffic congestion,this paper analyzes the correlation between lane changing behavior and traffic flow,and analyzes the effectiveness of inductive signal control scheme based on this input condition,providing an idea for the management and control method of urban expressway off ramp and junction.