Coordinative optimization strategy for group track maintenance planning and train scheduling of railways

Tracks are essential for ensuring the safety and reliability of railway transportation services. Due to the high-density operation of trains and exposure to open-air environmental conditions, components within the track system are susceptible to failure resulting from aging. The issue is typically addressed through concentrated preventive maintenance. However, the maintenance planning overlooks the influence of structural dependencies among track components and must be coordinated with the train timetable to be completed on time without affecting train operations. Therefore, this study proposes a coordinative optimization strategy for group track preventive maintenance planning and train scheduling considering structural dependencies. Track maintenance projects and activities are analyzed to illustrate the grouping conditions that consider structural dependencies, and a mixed-integer linear programming model is established to formulate this problem. Numerical experiments on multiple scales are presented to illustrate the sensitivity of the proposed approach. The impacts of maintenance capacity, group requirements, and the interval between trains traveling in the same direction on the model are also discussed. For the Guiyang-Kunming railway line, an actual case study demonstrated that the collaborative strategy enables a total cost reduction of 31.68%. Additionally, several recommendations are proposed for managers.