Timetable Optimization during Railway Infrastructure Maintenance

Maintenance activities are necessary to maintain the functionality of the railway infrastructure. Commonly, timetables are elaborated by considering the infrastructure unavailability periods caused by the performance of maintenance activities. However, sometimes unplanned maintenance activities have to be introduced at short notice, and the timetable must be rearranged to respect the new unavailabilities. Moreover, most of these activities require the presence of special maintenance trains which are typically not scheduled in the timetable and may have an impact on other train circulations. In this paper, we propose a mixed-integer linear programming formulation that rearranges a timetable to cope with the performance of maintenance activities. It includes the consideration of maintenance trains and other specific constraints, such as temporary speed restrictions. In this formulation, the rearrangement of the timetable is optimized based on a microscopic representation of both the infrastructure and the rolling stock. We assess two algorithms founded on this formulation on a real case study in the French railway network and we show their practical applicability.