Simulation And Lane Management Strategies For Mixed Traffic Flow Of CAVs And Human-driven Vehicles On Freeways

In recent years,there has been a high level of attention from the government and academia on the development of Connected Autonomous Vehicles(CAV),which have the potential to reduce traffic accidents,improve environmental pollution,and alleviate urban congestion.However,widespread application of CAV technology still requires more time,and in the foreseeable future,there will inevitably be a mixed traffic flow where Human-driven Vehicles(HV)and CAV coexist.The emergence of mixed traffic flow will change the traditional traffic flow composition and introduce new traffic characteristics.Due to the development of CAV technology and different mixing ratios,there are many uncertainties in the operating rules of mixed traffic flow.Despite research by scholars on the operating rules and traffic control strategies of CAV mixed traffic flow,there are still many uncertainties and unresolved issues.Therefore,this paper constructs a mixed traffic flow scenario composed of CAV and HV,conducts research on mixed traffic flow under different lane scenarios,proposes dedicated lane management strategies and shared lane management strategies,which are necessary to maximize the advantages of CAV and plan and manage mixed traffic flow.Firstly,the macroscopic and microscopic parameters of traffic flow are introduced,and the improved "Gipps safe distance" rule and the classic CACC and ACC models of the PATH laboratory are introduced into the cellular automaton,and the HV and CAV following models and lane-changing models are established.Using the NGSIM dataset,the parameters of the established HV following model are calibrated based on the genetic algorithm.Secondly,different mixed traffic flow scenarios are established on basic road sections,and the effects of different CAV reaction times,penetration rates,and lane-changing probabilities on traffic volume,vehicle operating speed,average passage time,and congestion are analyzed.Then,a dedicated lane management strategy for CAV on the eight-lane bidirectional freeway is proposed.The definition of the CAV dedicated lane is clarified,the setting method is determined,and the demand for CAV dedicated lanes is analyzed.A management strategy based on the number of CAV dedicated lanes is proposed,and the traffic efficiency and safety of each strategy are simulated and analyzed.Finally,a concept of allowing CAV to enter the High Occupancy Vehicle(HOV)lane is proposed,the development of HOV lanes is summarized,and four shared lane management strategies are proposed based on this.The traffic efficiency and safety of each strategy are analyzed.The results show that with the increase of CAV penetration rate,road traffic efficiency is improved,and the shorter the CAV reaction time,the higher the traffic efficiency.The increase in CAV lane-changing probability has a small impact on road capacity but can exacerbate road congestion.In addition,the construction of dedicated lanes for CAV should be based on a threshold condition of CAV penetration rate between 30% and 70%.Different lane management strategies can achieve optimal traffic efficiency and safety under different CAV penetration rates.For shared lane management strategies,different management strategies should be adopted based on the proportion of CAV and HOV to achieve optimal traffic efficiency and safety.The research results of this paper can provide important reference for road planners to effectively respond to future possible new mixed traffic flows and formulate more scientific and reasonable road planning and management strategies.