Adequate lateral resistance is required to provide the stable track structure necessary for safe rail operations on passenger and freight railroad track. Insufficient lateral resistance, coupled with a large thermal compression force in the rail from high rail temperature, can buckle the track structure. Railroads typically use mechanical stabilization, slow orders, or both, following maintenance operations that disturb the ballast section, such as track surfacing and alignment. Tests were conducted to improve the understanding of lateral resistance variations on concretetie track caused by surfacing and subsequent stabilization or compaction. Factors influencing track stability are summarized, maintenance procedures are described, the single-tie push test is described, and test results are presented. Tests were conducted to evaluate the changes in lateral resistance, from the trafficked, well-consolidated track structure before surfacing and alignment through the laterally weak track structure after surfacing. The influence of stabilization on the lateral resistance of the track structure was evaluated. The tests results indicate that surfacing significantly reduces the lateral stability of the track to a potentially critical level. Mechanical stabilization following surfacing significantly increased the lateral stability of all sections tested.

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Providing a safe, reliable, and maintainable railway infrastructure is a formidable challenge in Amtrak's complex operating environment. Presented is the design description of the Infrastructure Information Management database, including the latest developments and incorporating vehicle-track interaction measurements. Also shown is how wayside measurements combined with a record of train movement to define the traffic and utilization of the railway infrastructure. An example of the use of the system is discussed to illustrate how the combined information will assist the maintenance managers in determining when and where to invest resources to optimally maintain the railway infrastructure. Also addressed is how wayside and record of train movement can be used to allocate maintenance costs to the various service providers.

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The railroad industry uses slow orders, sometimes referred to as speed restrictions, in areas where an elevated rail temperature is expected in order to minimize the risk and consequence of derailment caused by track buckling due to excessive rail temperature. Traditionally, rail temperature has been approximated by adding a constant offset, most often 30°F, to a peak ambient air temperature. When this approximated maximum rail temperature exceeds a given risk threshold, slow orders are usually issued for a predefined period of the day. This “one size fits all” approach, however, is not effective and suitable in all situations. On very warm days, the difference between rail temperature and ambient air temperature can exceed railroad-employed offsets and remain elevated for extended periods of time. A given temperature offset may be well suited for certain regions and track buckling risk-related rail temperature thresholds but less accurate for others. Almost 160,000 hours of rail temperature measurements collected in 2012 across the eastern United States by two Class I railroads and predicted ambient air temperatures based on the National Weather Service’s National Centers for Environmental Prediction (NCEP) data were analyzed using detection theory in order to establish optimal values of offsets between air and rail temperatures as well as times when slow orders should be in place based on geographical location and the track buckling risk rail temperature threshold. This paper presents the results of the analysis and describes an improved procedure to manage heat-related slow orders based on ambient air temperatures.