Study Of Expressway Weaving Section Lane-changing Guidance Strategies Of Connected Vehicle

The weaving section is a typical bottleneck of urban roads.Due to the confluence and diversion of traffic flow,lots of vehicles change lanes in the weaving section,which leads to the decrease of traffic efficiency.Reasonable allocation of lane changing area for weaving vehicles that need lane changing and guidance of lane changing behavior of vehicles can effectively utilize the limited space in the weaving section and achieve the purpose of improving efficiency and reducing conflicts.Traffic management strategies combined with emerging intelligent connected technologies can facilitate access to information and guidance and control of vehicles.The lane-changing guidance strategy of interlaced sections researched in this paper is good for regulating the traffic flow in the weaving section and the bottleneck area of the ramp,alleviating traffic congestion and conflict,and improving traffic efficiency.The specific content is as follows:(1)Analysis of traffic flow in weaving section based on cellular transport model.The basic characteristics of the traffic flow in the weaving section are analyzed,and the factors affecting the traffic efficiency and traffic conflict are analyzed with the CTM.On the basis of this,lane changing guidance and ramp metering strategies are proposed,and the adaptability of the strategies under different traffic flow states is summarized.(2)Lane-changing guidance model for vehicles in weaving section.The traffic flow control framework of the weaving section under the intelligent network environment is put forward.The optimization model of lane-changing guidance for the upstream and weaving section is constructed.The ramp control model based on the ALINEA model is built;The combined control strategy flow of lane change guidance and ramp control is designed,and the combined control model of lane-changing guidance and ramp control in the weaving section is established to minimize the total travel time of the ramp area and the weaving section.Genetic algorithm is used to solve the model.(3)Simulation experiment and result analysis of the control strategy based on cellular automata.A traffic flow simulation scene is built and simulation parameters are set.The critical density of different control ways is determined by simulation.Take simulation results under the different densities of traffic flow,and get the traffic flow,speed,density,travel time as the evaluation index.The simulation results show that lane change guidance is enabled when the traffic flow density in the weaving section reaches 12 pcu /km/ln,and lane change guidance and ramp combined control are enabled when the traffic flow density in the weaving section reaches 25 pcu/km/ln.The higher the traffic flow density in the weaving section,the more obvious the control effect is.When the traffic flow density in the weaving section is 27 pcu /km/ln,lane changing guidance can reduce the average travel time of vehicles by 9s.When the mixing rate of networked vehicles is very high and very low,the control effect has little influence.When the mixing rate of networked vehicles is 40%-60%,the control effect is more sensitive to it.