A preliminary methodology for broken rail caused freight train derailment risk analysis

This paper investigates the influence of rail age, annual traffic density, and inspection frequency on broken-rail-caused train derailment risk. First, we estimate the probability of a broken-rail-caused train derailment based on a sequence of stochastic processes including rail defect formation, growth, detection and the likelihood that a broken rail causes a derailment. In addition to derailment frequency, we also estimate derailment severity, which is measured by the average number of railcars derailed per train derailment, based on FRA-reportable train derailment data. The preliminary risk analysis model provides a quantitative approach to understand broken rail risk, and potentially aid in development of effective ways to mitigate derailment risk.