Scheduling Infrastructure Renewal for Railway Networks

The pressing necessity to renew infrastructure assets in developed railway systems leads to an increased number of activities to be scheduled annually. Scheduling of renewal activities for a railway network is a critical task because these activities often require a significant amount of time and create a capacity conflict in operation scheduling. This paper discusses economic and technological aspects, opportunities, and constraints in the renewals of multiple rail infrastructure components at several locations in a railway network. We addressed and modeled a challenging situation in which there were interrelationships between different track lines, and thus, possession of a track line could affect the other track lines and prevent renewal works on them. A mathematical formulation for the railway infrastructure renewal scheduling problem in the network context was presented to minimize the total renewal and unavailability costs. A method based on a triple-prioritization rule and an optimal sharing of renewal times allocated for different types of rail infrastructure components in a possession is proposed to solve the problem. The method was applied to a real case of a regional railway network in Northern Netherlands and it was shown that up to 13% of total costs can be saved compared with the current scheduling practice.