Timetable Optimization for High-Speed Trains at Chinese Railways

We study the Train Timetabling Problem (TTP) of the high-speed trains at the Chinese railways. TTP calls for determining, in the planning phase, an optimal schedule for a given set of trains, while satisfying track capacity occupation constraints. In this work, we are given on input a set of feasible timetables for the trains already planned along a double-track high-speed line, and the main goal consists of scheduling as many additional trains as possible. Beside the main goal, a second objective is to obtain a regular schedule, i.e. a schedule showing regularity in the train frequency. We model TTP on a time-space graph and propose a heuristic algorithm for it. Preliminary computational results on real-world instances of the high-speed line from Beijing to Shanghai in China are reported.