Quantitative analysis of railroad train collisions in the United States

Train collisions are important because they are more likely to result in high consequence events compared to the two most common incident types on U.S. railroads, derailments and grade crossing collisions. On average, train collisions result in more casualties, cars derailed, and monetary damages per incident owing to involvement of multiple trains and the often-higher levels of kinetic energy. In this study, we analyzed train collision data from the U.S. Department of Transportation, Federal Railroad Administration (FRA) from 1997 to 2024. In addition to the collision types defined by FRA, we identified two new types of collision, derailment-caused and handbrake failure. We quantified the frequency, rate, and severity of train collisions and developed statistics on train types involved, type of trackage where they occurred, and the different causes. We developed an algorithm to identify striking and struck trains in collisions and quantified the differences in their characteristics. The extensive empirical FRA data on train collisions enabled us to define, identify, and quantify the different roles of trains in collisions with a resolution not previously achieved. Train collision rates declined during the time period considered in this study; however, several types of collision remained relatively unchanged. Collisions that positive train control (PTC) is intended to prevent began to decline 15 years before PTC was fully implemented on U.S. railroads. PTC is expected to eliminate most of these types of collision on lines so equipped; however, several important collision types are unaffected by PTC, particularly collisions caused by derailments. The causes of collisions on mainline/siding and yard/industry tracks differ for these two operating environments so different mitigation measures will be needed to reduce collision risk. The results provide new insights and understanding of train collision risk and will inform more effective approaches to improve train safety.