Dedicated Lanes Management Strategies For Automated Vehicles On The Highway Basic Roads

Autonomous driving dedicated lanes are emerging intelligent facilities on intelligent expressway.Their role and applicability have gradually attracted the attention of scholars,but they have not been fully studied at present.Therefore,this paper analyzes the mixed traffic flow under the influence of the dedicated lanes,and discusses their layout schemes under different traffic conditions,so as to provide reference for the future traffic management of intelligent expressway.The influence of dedicated lanes for automated vehicles on a mixed traffic flow can be analyzed with cooperative adaptive cruise control(CACC)strategies.The main purpose of this study is to analyze an influence of distribution of CACC flows on the traffic flow when there exist dedicated lanes.Existing Human-driving Vehicle(HV)model and the CACC model were used to establish capacity formula of a stable mixed traffic flow.Then,two CACC flow management strategies were proposed considering traffic demands,CACC market penetration rates,and capacity under a two-lane scenario consisting of a mixed-flow lane and a dedicated lane.The first one was a fixed strategy that a CACC flow was preferentially allocated towards a dedicated lane.The other one was a variable strategy that CACC flow was preferentially allocated toward a mixed-flow lane.An optimal CACC flow management method was demonstrated by comparing traffic volumes considering different traffic demands and penetration rates.Furthermore,the analysis is further extended to a multi-lane scenario.The correctness of the result was verified through case and simulated analyses.The simulations showed that the traffic flow is in a non-equilibrium state under the influence of the disturbance of vehicles,which cannot reach the theoretical equilibrium state.Therefore,the traffic capacity in both dedicated lane and mixed flow lane are less than their theoretical value.But the optimal allocation ratios obtained by simulation are basically the same as the theoretical values.The simulation results also show that lane changing behavior does not affect the optimality of fixed traffic management strategy.The dedicated lane management schemes under multilane scenarios are constructed,and a SUMO simulation platform is built based on the optimal CACC flow management strategy to simulate the lane management schemes.The simulation results show that the optimal number of dedicated lanes increases with the increase of penetration rate and traffic demand.Under the condition of low demand and penetration,the dedicated lane will restrain the traffic flow of the mixed-flow lane and reduce the utilization rate of dedicated lanes.The layout of dedicated lanes depends on the traffic demand of CACC vehicles and the capacity of dedicated lanes.In addition,lane-changing expands the applicable scope of dedicated lanes to some extent.In this paper,through the study of the key parameters influencing the lane layout,the flexible lane layout scheme is obtained,and the lane layout scheme under different traffic conditions is defined.