Maintenance routing for train units: The interchange model

Train units need regular preventive maintenance. Given the train units that require maintenance in the forthcoming 1–3 days, the rolling stock schedule must be adjusted so that these urgent units reach the maintenance facility in time. In this paper, we present an integer programming model for solving this problem, give complexity results, suggest solution methods, and report our computational results based on practical instances of NS Reizigers, the main Dutch operator of passenger trains.