多模式疏散交通车队配置与车道分配协同优化研究

考虑疏散交通的动态性和风险性，研究多模式疏散交通车队配置与车道分配的联合优化问题。首先，根据不同类型车辆的自由流速度，将路网离散为多尺寸元胞网络，采用元胞传输模型模拟混合交通流。然后，以最小化疏散总风险为目标，将多模式交通协同的动态疏散问题描述为混合整数线性规划模型，引入惩罚项消除因模型松弛产生的“车辆滞留”问题。在 NguyenDupuis路网中分析不同疏散需求下的最优车队配置、车道分配、疏散效率和疏散路径。结果表明：存在一个疏散交通需求区间，相比单模式疏散，组织多模式车队能够进一步降低疏散总风险， 而且最优的公交车配置比例呈阶梯变化；受路网通行能力限制，路网利用率存在上限；疏散总风险指标对疏散需求的变化比网络清空时间更敏感；多模式交通共享的路段一般位于临近风险源的出口通道，大容量的公交车优先占用最短路线，以提升疏散系统的效率。

Collaborative Optimization of Multimodal Evacuation Traffic Fleet Configuration and Lane Allocation

Considering the dynamics and risk of evacuation traffic, this paper focuses on the joint optimization of fleet configuration and lane allocations for multimodal evacuation traffic. Based on different free- flow speed, the study discretized the road network into multi-size cell network to load multimodal traffic flow via the cell transmission model (CTM). The multimodal traffic cooperative dynamic evacuation problem is formulated as a mixed integer linear programming (MILP) model to minimize the total travel risk of evacuees. The "vehicle holding-back" problem caused by model relaxation is eliminated by adding a penalty item. Numerical experiments are conducted in Nguyen-Dupuis network to analyze fleet configuration, lane allocation, evacuation efficiency, and routes under different evacuation demands. The results show that using multimodal fleet can further reduce the total risk of evacuation compared with single-mode fleet under certain evacuation demand, and the optimal bus proportion changes stepwise against evacuation demand; there is an upper boundary of road network utilization due to the limited road network capacity; the total evacuation risk is more sensitive to the change of evacuation demand than the network clearance time; the exit sections near the risk source are usually shared by multimodal traffic, and allocating the shortest path to high-capacity buses can improve the system efficiency.