A widely used measure for rail safety is accident rate, which is defined as the number of train accidents normalized by traffic exposure. Of interest in rail safety research is to understand the temporal trend of accident rates, the significant factors affecting the trend, as well as how to predict future accident rates. This paper presents a statistical analysis of U.S. freight-train derailment rates from 2000 to 2012, based on information from the Federal Railroad Administration of the U.S. Department of Transportation. The analysis leads to several observations, including:
• There is a significant temporal decline in Class I freight-train derailment rate (−5.8%) per year
• The rate of change in accident rate varies by accident cause. Freight-train derailment rates due to broken rails or welds and track geometry defects declined by 7% annually, respectively; bearing-failure-caused derailment rate decreased by 11% annually; and derailment rate caused by train handling errors fell by 9% annually.
Future train derailment rates are projected and can be used to evaluate the safety benefit of accident prevention strategies.