为解决采用传统Dijkstra 算法在高速公路应急疏散规划路径中存在可用性差的缺陷，考虑 高速公路路网中有通行容量及条件限制的节点和路段特征，对其进行改进，提出容量限制节点的 表征方式及流量计算方法，并根据待疏散车辆特征对具有限高、限重属性的路段进行筛选，提出 分类路径规划方法。最后，以河南省高速公路局部路网疏散路径规划问题为基础设计算例，分别 采用传统算法和改进Dijkstra 算法对高速公路应急疏散路径进行求解。结果显示，传统算法得到 的路径规划及交通量分配结果中，容量限制节点上游路段的分配交通量高于节点容量，在节点处 形成疏散瓶颈，且对于规划路径中有限重条件的路段，案例中超重车辆无法使用该路段疏散；相 比而言，由改进算法得到的路径规划及交通量分配结果则不存在上述问题，从而使得疏散效率和 疏散路径的可用性得到了保证。

Traditional Dijkstra algorithm has the defect of poor availability in route planning of expressway emergency evacuation. In order to solve this problem, an improved Dijkstra algorithm was presented, considering the characteristics of links and nodes with traffic restriction in expressway network.A new representation mode of nodes with capacity restriction and traffic volume calculation method was proposed. According to the characteristics of vehicles to be evacuated, a classified route planning method was proposed by filtrating the sections of expressway with height and weight restriction. Furthermore, based on an emergency evacuation case in Henan expressway system, a numerical experiment was estab⁃ lished and its problems were solved by using traditional algorithm and improved Dijkstra algorithm respectively.The result showed that the distributed traffic volume on upstream section was higher than the upper limit of node capacity in route planning and traffic distribution using traditional algorithm, which may lead to evacuation bottlenecks. Meanwhile, overweight vehicles weren′t able to be evacuated in sections of expressway with weight restriction. In comparison, there were no such problems above using improved Dijkstra algorithm, and the evacuation efficiency and the availability of evacuation route were improved by using the new method.