| The relative closeness of urban expressway makes on-off-ramp and ground road adjacent area become the area with frequent traffic congestion,which leads to the traffic problems of on-ramp "unable to get on" and off-ramp "unable to get off".In particular,as the key of traffic control,off-ramp and ground road adjacent area,when the traffic demand is large,multiple traffic flows converge and interweave in the connection area,which is easy to cause traffic congestion.This research summarizes the traffic characteristics and traffic organization of the expressway off-ramp and ground road adjacent area,analyzes the reasons of congestion in adjacent area,and proposes the control method of off-ramp and adjacent intersection under connected vehicle environment,so as to improve the traffic efficiency of adjacent area and intersection.To improve the traffic efficiency of the urban expressway off-ramp and ground road adjacent area,a multi-stage control method is proposed for the off-ramp and ground road adjacent area under connected vehicle environment.Firstly,according to the speed characteristics,the adjacent area is divided into adjustment area,buffer area and queuing area.Then,in view of the problem of frequent conflicts between vehicles in adjacent area,a lane-changing strategy is proposed considering phase priority.Finally,based on this,a three-stage control strategy is designed for the off-ramp and ground road adjacent area,and the simulation environment of connected vehicle is built based on MATLAB and VISSIM.The simulation results show that the proposed method can make the speed fluctuation smaller between each road section and the average speed is increased by 5%;compared with the speed control under connected vehicle environment,the delay of the adjacent area,queuing area and buffer area is reduced by 4%,6% and 4% respectively.In addition,the sensitivity analysis shows that when the traffic demand is in the medium saturation and the penetration rate is more than 70%,the control effect of this method is the most obvious.Based on the control of connected vehicle on expressway off-ramp and ground road adjacent area,considering the traffic efficiency of other entrances of the adjacent intersection,the off-ramp,the auxiliary road and the adjacent intersection are jointly controlled.The objective function is to minimize the average delay and the average number of stops.This research establishes the joint control model of off-ramp and adjacent intersection under the connected vehicle environment,solves it through NSGA-II algorithm.The simulation results show that compared with the adaptive control,the delay and number of stops in the area of off-ramp and adjacent intersection are reduced by 44% and 14.3%.The sensitivity analysis shows that different communication distance has little effect on the delay of adjacent intersection under medium saturation and low permeability.The relevant results can provide theoretical support for the off-ramp and adjacent intersection under connected vehicle environment. |
