A pragmatic algorithm for the train-set routing: The case of Korea high-speed railway

This paper presents a two-phased train-set routing algorithm to cover a weekly train timetable with minimal working days of a minimal number of train-sets. First, relax maintenance requirements and obtain minimum cost routes by solving the polynomial relaxation. Then, maintenance-feasible routes are generated from the crossovers of the minimum cost routes. This pragmatic approach seems particularly effective for the high-speed railway systems, where the railway topology is relatively simple with few end stations while the trains are frequent. Applied to the current weekly timetable of the Korea high-speed railway, we could find an optimal feasible routing, which is an 8.8% improvement over the current routing generated by a set partitioning approach based on a path generation scheme.