The positive effects of under sleeper pads have already been proven by track and laboratory tests worldwide. In Austria, padded concrete sleepers reduce track deterioration by 50 percent and have therefore been used as standard components since 2010. As the pads increase material costs, many infrastructure managers have discussed the idea of covering costs by reducing the ballast bed thickness. Technically, this approach (less ballast) is feasible, as the pads increase the track elasticity and protect the ballast. Further, pads lead to higher rail deflection and distribution of the load to more sleepers, and the stresses in sleepers are therefore relieved. Here, we compared Austrian test sections with padded and unpadded concrete sleepers and with a difference in the ballast bed thickness: standard thickness of 30 cm against 20 cm below the sleeper. Fractal analyses and standard deviations of the track’s longitudinal level provided information about the sections’ long-term track behaviour over 20 years. We found that the standard solution with 30 cm ballast performed better in the long term compared to 20 cm. Additionally, the test section with padded sleepers on a reduced ballast bed thickness showed a lower maintenance demand than the unpadded concrete sleeper track on a 30 cm ballast bed.

Transport volume is often addressed as gross-tonnage when it comes to track degradation, maintenance needs and maintenance costs. Tonnage and thus weight are insufficient to address track loading: The vehicle properties, mainly axle load, unsprung masses and bogie stiffness, as well as train speed have a major impact on track maintenance demand. This chapter gives an overview on vehicle-specific track deterioration models and describes the maintenance needs of different track as well as the influence on track maintenance cost of different vehicles and trains. The approach proposed is both simple enough to be used and sufficiently detailed to address the main technical aspects. The differences of track maintenance necessary for mixed traffic lines, high-speed lines and heavy haul freight lines can be derived from the vehicles used and the existing train speeds. In passenger transport, the difference between push-pull loco hauled trains (with wagons) and multiple units are a major aspect.