基于动态分流元胞传输模型的城市道路网络韧性评估

为全面评估重大扰动事件下城市道路网络抵御扰动并从扰动中快速恢复的能力，提出以改进元胞传输模型模拟路网流量分布状态，以韧性为测度指标的路网性能评估模型。针对传统元胞传输模型交叉口分流比例恒定的不足，明确考虑扰动事件影响期内因出行者调整路径可能导致的路径流量波动，构建出行决策行为与元胞流量传输的强耦合机制，提出一种新的动态分流元胞传输模型；基于动态分流元胞传输模型获得的路网性能参数，以路网效率为路网基础性能指标，构建反映扰动事件影响期内路网效率累积动态变化的韧性指标；并基于Sioux Falls网络开展算例研究。算例结果表明：相比传统元胞传输模型，提出的动态分流元胞传输模型通过设置交叉口动态分流参数，建立出行决策行为与元胞流量传输的动态耦合关系和路径流量变化与交叉口元胞分流比例的自洽机制，可准确描述路网实际流量分布状态；提出的基于路网效率的韧性指标可全面反映扰动事件发生后路网性能退化到恢复全过程的动态累积性能，直观展示路网抵御扰动并从扰动中恢复的能力，契合韧性内涵；韧性评估中若忽视出行决策行为潜在影响，将获得次优甚至明显偏离实际的方案或结果。

Resilience Assessment on Urban Road Network by Dynamic Shunt Cell Transmission Model

To comprehensively evaluate the ability of urban road networks to resist and recover quickly from major disturbances, a road network performance evaluation model based on an improved cell transmission model is proposed to simulate the flow distribution of the road network and to compute the network resilience as an index. To address the weakness of the constant shunting ratio at intersections in the traditional cell transmission models, the path flow fluctuation caused by travelers' path adjustment during the disturbance events is clearly considered, and the strong coupling mechanism between travel decision behavior and cell traffic transmission is constructed, and a novel dynamic shunting cellular transmission model is proposed. Based on the network performance parameters obtained by the dynamic shunt cell transmission model, the road network efficiency is taken as the basic performance index, and a resilience index reflecting the cumulative dynamic changes of the road network efficiency during the disturbance event was constructed. Finally, a case study is carried out based on the Sioux Falls network. The results show that, compared with the traditional cell transmission model, the proposed dynamic shunt cell transmission model can accurately describe the actual traffic distribution state of the road network by the dynamic coupling relationship between travel decision-making behavior and cellular traffic transmission and the self-consistent mechanism between path flow variation and the proportion of cellular traffic at intersections. The resilience index based on the network efficiency can comprehensively reflect the dynamic cumulative performance during the whole process from the network performance degradation to recovery after the disturbance events, which intuitively shows the ability of the road network to resist and recover from the disturbances. If the potential impact of travel decision-making behavior is ignored, the resilience assessment will be not accurate.