| The bidirectional four-lane expressway built in the early stage has been unable to meet the growing demand of intercity transportation,and the maintenance or reconstruction and expansion of infrastructure is increasing day by day,which has a certain impact on vehicle operation.At the same time,with the advancement of vehicle network intelligent process,it will become an inevitable trend for artificial driving vehicles and intelligent network vehicles to run together in the future,and the traffic organization design of construction areas will encounter new challenges.Therefore,this paper relies on the basic research funds of the central universities "Expressway Network Assisted Driving Mixed Traffic Flow Modeling and Simulation Research(300102341201)",takes the expressway construction area as the research scene,analyzes the road and traffic operation characteristics in the construction area,and builds a micro traffic flow model.Through numerical simulation,the operation characteristics of traffic flow in expressway construction area are studied.The main contents are as follows:(1)The research scene was defined as the closed construction area of one-way outer lane and the functional division of each section.The operating characteristics of road and traffic flow in the construction area were summarized,and the behavioral characteristics of humandriven vehicles and intelligent networked vehicles were analyzed.The video image processing software George2.1 is used to extract the vehicle running data from the surveillance video of the construction area,and the distribution characteristics of traffic flow in speed,time headway and lane change position are studied.(2)Based on the traffic operation characteristics in the construction area,the Na Sch model and STCA model were improved,and the following model,free lane change and forced lane change models were constructed.At the same time,formation rules were established for the intelligent network vehicle queue scene.Using the actual vehicle running data and the existing research results,calibrate the vehicle micro-model parameters;The basic map model of mixed traffic flow was constructed,and the parameter sensitivity analysis was carried out.(3)The simulation scene of expressway construction area with only manual driving vehicles was established,and the influence of traffic organization design on traffic flow operation efficiency was studied by analyzing the characteristics of traffic capacity and location spatio-temporal map.The traffic flow safety evaluation index system was constructed,and the influence of traffic organization design in construction area on speed standard deviation,integrated collision time and rear-end collision risk index was analyzed.The results show that when the starting position of the confluence is 1000 m,the speed limit is 60km/h,and the length of the upstream transition zone is 160 m,the operation efficiency and safety of the traffic flow in the construction area are relatively good.(4)Based on the research conclusion of traffic organization design in construction area,the simulation scene of expressway construction area mixed with intelligent networked vehicles is constructed.By adjusting the mixing rate and the maximum size of the fleet,the influence law of intelligent networked vehicles on the traffic flow in construction area is analyzed.The results show that the blending of intelligent networked vehicles can continuously alleviate the degree of traffic flow congestion and improve the safety at a high blending rate.Queue driving can further improve operation efficiency,but it has adverse effects on safety when the fleet size is small.This negative effect is significantly improved or even better when the maximum size is 8-10. |
