Development of an integrated model for the evaluation and planning of railroad track maintenance

In order for a railroad to function effectively all aspects of the system should be maintained in good working order. Locomotives and rolling stock regularly move through areas where they can be inspected and maintained. However track does not move, so inspectors must traverse the line either on foot or in a rail mounted vehicle and maintenance crews must be sent to specific locations to make track repairs, which may not always happen before a service disruption. A track failure, due to either exceeding some industry or governmental specification or an acute failure, such as a rail break, can result in costly delays or even derailments with significant consequences. To help avoid such failures, it is beneficial for a railroad to be able to predict when and where failures might occur and then evaluate the relative costs and benefits of performing maintenance activities to ensure that the most cost effective actions are taken. A model is being developed to assist in the process of scheduling and directing track maintenance work. The model consists of three primary modules: an integrated track quality and degradation module, a maintenance activity selection module, and a scheduling optimization module. By taking into account a wide range of costs and benefits, the model can help railroad infrastructure managers better account for risk and indirect costs such as track time, as well as account for the criticality of certain types of imminent failures. This paper will describe the inputs and outputs for the model, as well as detailing the concepts associated with each of the model components.