考虑动态交通流的停车场车辆最优疏散模型

为有效地制定停车场车辆疏散方案，缩短车辆疏散时间，研究了考虑道路网动态交通流特征的停车场车辆最优疏散模型. 首先，根据排队论将停车场每个出口车道的车辆排队抽象成一个M/M/1/1排队系统，分析出口道路交通流车头时距对车辆离开率的影响，从而估算车辆在停车场内的排队时间. 其次，构建道路网节点交通流均衡模型和路段交通流均衡模型模拟车辆的疏散路径选择行为，并估算疏散车辆的行驶时间以及在交叉口的延误时间. 最后，选取一个具有4个出口的停车场进行车辆疏散仿真模拟. 研究结果表明:出口处道路交通流车头时距对停车场车辆排队时间、行驶时间和总疏散时间均有显著影响，并且车辆在道路网中最优路径的选择主要受非疏散交通流影响；该模型能模拟停车场车辆在疏散过程中的动态交通特征及时间消耗，根据出口处道路交通流车头时距动态调整车辆离开率，提升疏散效率. 

Optimal Evacuation Model of Parking Vehicles in Dynamic Traffic Flows

In order to develop an effective evacuation plan for vehicles in a parking lot and achieve the shortest evacuation time, an optimal evacuation model was built by considering the dynamic traffic flow characteristics of a road network. Firstly, according to queuing theory, the vehicle queue on each exit lane of a parking lot was denoted by an M/M/1/1 queuing system, which was used to simulate how the traffic flow headway on the exit lane affects the vehicle departure rate, and estimate the queue time of the vehicles in the parking lot. Secondly, the traffic flow equilibrium model of road network nodes and link traffic flow equilibrium model were employed to imitate the path selection behavior in vehicle evacuation, and the evacuation time and delay time at intersections were estimated. Finally, a parking lot with 4 exits was selected to conduct an evacuation simulation. The results show that the traffic flow headway on the exit lane has a significant impact on vehicle queue time, travel time and evacuation time, while the optimal route choices are mainly affected by background traffic, demonstrating that the proposed model can simulate the dynamic traffic characteristics and time consumption during the evacuation process and adjust the departure rate to improve the evacuation efficiency according to the traffic flow headway.