Strategic Model to Optimize Railway-Track Renewal Operations at a Network Level

This paper presents an optimization model for scheduling railway ballast, rail, and sleeper renewal operations at a network level. The objective of the model is to minimize the expected railway track life-cycle cost (LCC) and track unavailability costs derived from user impacts caused by traffic disruption during track renewal operations. To minimize costs, the model assesses the opportunistic renewal of railway track components and takes advantage of planning from a network perspective to study the possibility of reusing track components on different lines. The practical utility of the model is illustrated with a case study involving the Portuguese railway network. The results indicate that user costs have an important influence on decision making in the track renewal process and that the network perspective of renewal planning can reduce the direct costs of these operations. (C) 2016 American Society of Civil Engineers.