Track Maintenance Costing: Alternative Approaches
Date
1993-10
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Abstract
Determination of the costs of operation is essential in any business environment that deals with complex multiple user situations. This is particularly true in the railroad industry where proper understanding of costs and cost contributions is difficult to achieve. Railroads carry many different commodities, moving in a variety of cars of different sizes and weights and in trains of varying length, motive power assignments, and maximum operating speeds. The effect on costs of an incremental change in operating parameters or practices is difficult to accurately quantify. This is particularly true for maintenance of way costs, and specifically the relationship between maintenance of way costs and traffic volumes. This has always been a problem in track maintenance decision making, how to accurately determine the rate of failure of track components and thus the cost of maintaining the track structure, to keep ahead of track degradation. Deferred maintenance and the practice of allowing track conditions to deteriorate over short periods of financial difficulties compound this problem. These difficulties are accentuated by non-linear damage effects such as those caused by axle loading and environmental factors. These damage effects translate into non-linear cost sensitivities. Further increasing the difficulty in defining track maintenance costs are the conflicting trade-offs that are inherent in high-density tracks. While high densities do allow for some economies of scale in maintenance of way practices, they also result in limited maintenance access, which in turn drive up costs. Furthermore, the level of traffic density has a major impact on costs. On lightly used rail lines, increases in traffic can be accommodated with only small increases in the cost of track maintenance. But as traffic continues to increase, the environmental mechanisms that limit track component life when no traffic uses a track (rust and decay) become insignificant on heavily trafficked railroads. Rust and decay are replaced by abrasive wear and crushing; rails and ties do not remain in track long enough for environmental mechanisms to dominate life. Several widely employed costing methodologies rely heavily on an economy of density effect. This assumption can lead to a misspecification of incremental track maintenance costs as traffic density increases. It can further result in an improper allocation of budgetary resources for track maintenance, particularly on the highest density routes, which are generally the most sensitive to the level of maintenance and condition of the track. Therefore, it is important to both maintenance of way officers and to senior railroad management that accurate track maintenance costs be obtained and used in the planning and budgeting process.
Description
Keywords
Track maintenance, Track structure
Citation
Zarembski, A. M., “Track Maintenance Costing: Alternative Approaches”, Conference on Maintaining Railway Track; Determining Cost and Allocating Resources, Arlington, VA, October 1993.