Sensitivity Analysis of Track Maintenance Strategies for the High Speed Rail (HSR) Services

Abstract

Track Maintenance (TM) is one of the critical parts of rail operations and asset management. It has been estimated that about 25–35% of all operational costs are related to the track maintenance performance which can be typically classified as either corrective maintenance (CM) or preventive maintenance (PM). The first is a more reactive approach, where maintenance is conducted when inspections have revealed a need for action. The latter is a strategic approach that is mainly applied through maintenance planning. High Speed Rail (HSR) systems, especially on shared HSR corridors, can complicate track maintenance conditions due to the tight tolerances and precision, reliability and safety issues required by HSR. This paper evaluates strategic approaches for track maintenance planning along selected HSR corridors with either shared or dedicated operation pattern. The paper uses analytical and descriptive parameter tables to evaluate how sensitive a corridor is to changes in essential criteria for developing track maintenance strategies (TMS). These criteria may include: - HSR traffic conditions and operations regime; - TMS approach (or strategy) on current rail lines connected to the new HSR line; - Operation and Maintenance (O&M) structure of HSR management system. The descriptive parameter tables have been used by a specific PM modeling approach called preventive maintenance scheduling problem (PMSP). Before running PMSP model over a designated line, the respective parameters of the model should be calibrated and analyzed based on the line specifications. The descriptive parameter tables can be used during calibration procedure to assist in analyzing the sensitivity of model’s parameters and variables for the above mentioned criteria. This paper discusses and compares TMS approaches on three planned HSR corridors in Europe (Lisbon-Madrid HSR), Asia (Tehran-Isfahan HSR) and USA (California HSR). All three HSR rail corridors are under development, but each presents specific sensitivities to the given PM model’s parameters that can affect track maintenance strategic planning along these corridors. We concluded that TMS model calibration by these descriptive analytical tables can assist maintenance strategic planners in identifying different TMS approaches when dealing with maintenance contractors, HSR operators and public rail authorities.