LCC Based Requirement Specification for Railway Track System

Life cycle cost (LCC) analysis is a key tool for effective infrastructure management. It is an essential decision support methodology for selection, design, development, construction, and maintenance of railway infrastructure system. Effective implementation of LCC analysis will assure cost-effective operation of railways from both investment and life-cycle perspectives. A major setback in the successful implementation of LCC by infrastructure managers is the availability of relevant, reliable, and structured data. Another challenge is the prediction of future behaviour of railway system with a change in the design or operation parameters. Different cost estimation methods and prediction models have been developed to deal with both challenges. However, there is a need to integrate prediction models as an integral part of LCC methodology, to account for possible changes in the model variables. This article presents an LCC based approach for requirement specification. It integrates degradation models with an LCC model to study the impact of change in design speed on key decision criteria such as track possession time, service life of track system, and LCC. The methodology is applied to an ongoing railway investment project in Sweden to investigate and quantify the impact of design speed change from 250 to 320 km/h. This is carried out to support specification of technical requirement for the design of track system. The results from the studied degradation models show that the correction factor for a change in speed varies between 0,79 and 0,96. Using this correction factor to compensate for changes in design speed, the service life of ballasted track system is estimated to decrease by an average of 15% from 30 years to approximately 25 years. Further, the LCC of the route under consideration will increase by an expected value of 30%.