Abstract: Evacuation vehicles and rescue vehicles should have different traffic priorities on the road network under local emergencies, e.g., explosion and leakage of hazardous chemicals, fire explosion, etc. This paper investigates a coordinative optimization problem of a multi-priority multi-class dynamic emergency traffic network. Firstly, considering the difference in traffic priority, the dynamic traffic loading process of evacuation and rescue vehicles on the road network is simulated by relaxing the link transmission model, and turning conflict elimination at intersections and link contraflow constraints are also integrated. Since contraflow strategies adopted by high-priority vehicles occupy the traffic capacity of low-priority vehicles, the limitation of the number of contraflow links is set to rescue vehicles. And then, a stage-based optimization method is designed to solve the proposed multi-objective mixed integer linear programming model of multi-priority multi-class dynamic emergency traffic network (MPCDETN-MMILP). Taking the Nguyen-Dupuis network as an example, the impact of the number of contraflow links occupied by highpriority vehicles on evacuation and rescue traffic is analyzed. The results of the numerical example show that there are upper limits for both the number of rescue traffic contraflow links and improving the corresponding performance of rescue vehicles to arrive at the disaster area. Moreover, the improvement trend of the rescue traffic optimization gradually slows down, and the inhibition of rescue traffic contraflow links on the quick arrival of evacuation vehicles at the safe area shows the fluctuating increasing trend. The number of contraflow links used by rescue traffic has a significant coordinating effect on evacuation and rescue traffic operation performance oriented to rescue priority. In addition, the links which connect the disaster area and the outside rescue station and can compose the shortest route is more likely to be set as contraflow link of rescue traffic.

Key words: urban traffic, multi-priority multi-class traffic, dynamic emergency traffic network, contraflow strategies, coordinative optimization

摘要： 危化品爆炸泄漏和火灾爆炸等局部突发事件下，疏散车辆与救援车辆在路网上通行的优先级具有差异性。为研究多优先级多车种动态应急交通网络协调优化问题，本文根据多车种的优先级差异性，松弛路段传输模型，模拟疏散和救援交通在路网上的动态加载过程，引入交叉口冲突转向消除与道路反流约束；考虑到优先通行车辆的反流策略会占用低优先级车辆的道路通行能力，设置救援交通的逆行路段数限制。设计分阶段优化方法求解多优先级多车种动态应急交通网络协调优化的多目标混合整数线性规划模型(MPCDETN-MMILP)。最后，以 NguyenDupuis路网为例，分析优先通行车辆使用的逆行路段数对疏散和救援交通的影响。算例结果表明：救援交通逆行路段数和对救援车辆迅速到达受灾区域的提升存在上限，且这种提升趋势是逐渐变缓的，而对疏散车辆迅速到达安全区域的抑制呈现波动式的增加趋势；救援交通逆行路段数对救援优先的疏散和救援交通运行优化效果有较大协调作用；连接受灾区域和外部救援场站，且可构成最短径路的路段更会被选择为救援交通逆行路段。

关键词: 城市交通, 多优先级多车种, 动态应急交通网络, 反流策略, 协调优化