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在城市轨道交通中，随着各条线路的末班车按运行计划逐站完成载客任务，路网上OD两点间的可达路径逐渐变少，直至两点间不可达，这样的路网服务能力随时间的动态变化，称为动态可达性。本文研究运行计划约束下的路网动态可达性计算方法，以支持末班车开行的优化，实现搭乘末班车出行乘客目的地可达的最大化。本文首先分析了末班车开行带来的动态可达性，给出了最晚可达时间、路径可达性、OD可达性定义。在此基础上，提出了末班车开行下路网可达性的计算方法与最晚可达时间求解的递归算法。最后，以路网可达性最大为目标，将可达性计算方法应用于末班车换乘衔接优化。通过算例分析验证了可达性计算方法的有效性。

Analyzing and Computing Dynamic Accessibility with Constraints of Schedule

When time close to the running of last trains, the number of active routes in urban rail transit will become less and less. The network accessibility changing along with the time is called dynamic accessibility. The method about computing dynamic accessibility is studied, which fits to the planning of last trains and improves the service quantity to passengers who want to take very late or even last trains to their destinations. These definitions are given, such as latest accessible time, route accessibility and OD accessibility. Then, the main steps to compute network accessibility with last trains running is presented, and a recursive algorithm is used to compute the latest accessible time. At last, a flow of applying network accessibility is proposed to optimize the connection scheme of last trains. The example is given to demonstrate the feasibility of the method.