This paper develops an operational strategy in which urban rail transit is used for freight transport. An environment-friendly urban freight transportation alternative is analyzed by employing optimization techniques to support the collaborative transportation of passengers and freight. Practical cases are investigated to test the technical feasibility of this transportation scheme. The paper formulates the train service design problem on a single urban rail line with passenger and freight. Passenger trains have a prescribed timetable which is allowed to be slightly modified to facilitate the freight service. Freight can be transported by inserting dedicated freight trains or utilizing the extra space inside the passenger train carriages. Station platforms are able to load and unload both goods and passengers. An optimization model for combined train service design is proposed to maximize profit resulting from the balance of revenues and costs brought by the freight service. The efficient schedules of trains and freight allocation plans are to be determined. This problem is formulated as a mixed-integer linear programming model. An iterative scheduling approach which includes a pre-processing method and two heuristic iterative algorithms is designed to solve the model. Two numerical examples are introduced to demonstrate the efficiency of the proposed model and the iterative scheduling approach.

本文制定了一种将城市轨道交通用于货运的经营策略。通过采用优化技术来支持乘客和货物的协同运输，分析了一种环境友好的城市货运替代方案。对实际案例进行了研究，以测试该运输方案的技术可行性。本文提出了一条载客货运的城市铁路线上的列车服务设计问题。旅客列车有规定的时间表，可以稍作修改以方便货运。可以通过插入专用货运列车或利用旅客列车车厢内的额外空间来运输货物。站台能够装载和卸载货物和乘客。提出了一种组合列车服务设计的优化模型，以使货运服务带来的收支平衡达到最大的利润。确定有效的火车时刻表和货运分配计划。此问题被公式化为混合整数线性规划模型。设计了一种包含预处理方法和两种启发式迭代算法的迭代调度方法来求解模型。介绍了两个数值示例，以证明所提出模型和迭代调度方法的效率。此问题被公式化为混合整数线性规划模型。设计了一种包含预处理方法和两种启发式迭代算法的迭代调度方法来求解模型。介绍了两个数值示例，以证明所提出模型和迭代调度方法的效率。此问题被公式化为混合整数线性规划模型。设计了一种包含预处理方法和两种启发式迭代算法的迭代调度方法来求解模型。介绍了两个数值示例，以证明所提出模型和迭代调度方法的效率。