基于动态清空距离的特殊车辆与CAVs混合车道控制

特殊车辆的优先通行是道路交通管理的一项重要工作，而目前相关控制措施存在实施难度较大、道路空间利用率低和道路通行能力下降等问题。为解决这些问题，结合智能网联汽车（CAVs）技术特点，提出考虑特殊车辆优先通行的CAVs专用车道控制方法，按应急车辆、一般优先级车辆和CAVs的优先通行顺序设计车辆通行规则。通过预测特殊车辆到达下游交叉口时的路口排队长度，建立“满足不同优先级特殊车辆通行需求”的动态清空距离模型，其中应急车辆以速度损失最小化为优化目标，一般优先级车辆以均衡车辆通行需求为优化目标。针对CAVs在专用道上可能成为其他车辆通行障碍的情况，考虑换道安全和不同换道动机，设计CAVs进入和离开专用道的规则，建立换道决策控制模型；在此基础上，提出适用于不同优先级车辆的专用车道通行控制策略。通过仿真实验对所提方法的控制效果予以分析验证。实验结果表明:与不考虑特殊车辆优先通行的控制方法相比，虽然该方法的车均出行时间和人均出行时间分别增加了3.9%和2.8%，但特殊车辆的车均延误时间减少了59.6%以上；与IBL控制方法相比，该方法的车均出行时间和人均出行时间分别减少16.7%和14.6%，特殊车辆的车均延误时间减少13.5%，专用车道利用率提高36.3%以上，并且在CAVs渗透率大于0.4时获得最佳控制效果。该控制方法在特殊车辆优先通行方面，减少了单一控制策略的局限性，为交通控制和管理提供理论支撑。 

A Control method of Dedicated Lanes for Mixed Use of Special Vehicles and CAVs Based on Dynamic Clear Distance

Providing road priority to special vehicles is one of important tasks of traffic management and operation authorities. However, traditional control measures for providing road priority to special vehicle are difficult to implement, and they also tend to significantly reduce road capacity for other traffic. Therefore, a control method of dedicated lane for mixed use of special vehicles and connected automated vehicles(CAVs), is proposed to solve the above problems. First, the access rules for the dedicated lanes in the order of emergency vehicles, vehicles with secondary priority and CAVs are designed. By predicting the queue length when special vehicles arrive at a downstream intersection, the state of special vehicles at the intersection is obtained, and a dynamic clear distance model is developed to meet the demand of special vehicles with different priorities. In this model, the objective function is to minimize the speed reduction of emergency vehicles, and to balance the road capacity with traffic demand of the vehicles with secondary priority. The rules for CAVs to enter and leave the dedicated lanes are designed, and a lane-changing control model is established to solve the problem that CAVs may become obstacles to other vehicles at dedicated lanes. With the above, a dedicated lane control strategy suitable for different types of vehicles with different priority is proposed. The effectiveness of the model is validated through a set of simulated experiments. Study results show that, compared with the control methods without consideration of the priority of special vehicles, the average travel time and per capita travel time are increased by 3.9% and 2.8% respectively, but the average vehicle delay of special vehicles is reduced by more than 59.6%. Compared with the intermittent bus lane control method, the average vehicle travel time and per capita travel time are reduced by 16.7% and 14.6% respectively, and the average delay of special vehicles is reduced by 13.5% and the use rate of special lanes is increased by more than 36.3%. The best outcomes can be obtained when the CAVs penetration rate is greater than 40%. The proposed method removes some of the limitations of traditional lane control strategies when providing road priority to special vehicles, and therefore, provides"new"theoretical contribution for traffic control and management.