Study On Traffic Flow Characteristics Of Weaving Segments Of Interchange Based On Traffic Safety

Interchange is an important part of highway,which is an important facility to realize the traffic flow of the road network.It plays a key role in the traffic safety of highway,and especially weaving segments in them are the bottleneck of traffic safety for its unique operation features.To improve traffic safety and operation of weaving segments.This paper focuses on the characteristics of traffic flow in weaving segments of freeway and reveals the mechanism and regularity of traffic flow.Based on the above,the characteristics of traffic flow characteristics of intertwined areas are determined,and the relationship between traffic flow characteristics and traffic safety is analyzed.First of all,this paper summarizes the relationship between traffic flow characteristics and traffic safety in the existing research by consulting a large number of documents.After analyzed the structures and operating characteristics of weaving segments,this paper identifies the characteristics of velocity,follow-up and lane change as the main characteristics of traffic safety.On the basis of this,a detailed investigation program is developed,and the weaving segments of Nanjing Marco Hub is selected as the survey object.According to the obtained traffic flow data,the spatial and temporal distribution of traffic volume,velocity dispersion characteristics,vehicle follow-up behavior and vehicle roadway behavior are analyzed.In the paper,the weaving segment model is established by VISSIM software,and the measured data is used to calibrate and test the simulation model.Through the simulation program,this paper selects speed standard deviation coefficient and average lane change times of all vehicles as the main indexes that reveals the traffic safety of weaving segments.According to the results of the simulation experiments,the statistical regression models of velocity standard deviation coefficient and average lane change times of all vehicles between traffic flow,length of weaving segments,ratio of weaving flow to the total flow,and mix rate of large vehicles are built.Finally,this paper reorganized the existing researching data.By using the cumulative frequency of the accident rate,the traffic safety evaluation standard of the weaving segments based on the speed standard deviation coefficient is determined.This paper also put forward an applied example,and the result between the simulation data and actual traffic accidents data also reflects that the method is effective in some extent.