Statistical and geospatial comparison of trends in freight train handling and make-up derailments by characteristics and track topography

From 2012 to 2017 there were 101 freight train handling and make-up accidents on the mainlines of the four largest Class I railroads in the United States; from 2018 to 2023 there were 177 such accidents, an increase of 75%. Coincident with this substantial change in freight train safety, North American railroads implemented new operating practices favoring longer freight trains, especially after 2018, and experienced labor shortages leading to reduced train crew experience during the years immediately following the COVID-19 pandemic. Both of these trends may lead to train handling and make-up challenges across different railroad track topographies. Instantaneous track features such as sharp curves or steep grades may increase the difficulty in handling longer trains safely due to intensified in-train forces. Broader patterns of repeated horizontal curves and vertical undulation requiring rapid throttle and brake commands may pose challenges for inexperienced train crews. This raises the question of if the train characteristics and track topography associated with train handling and make-up derailments have changed as their frequency has increased. A GIS-based methodology is proposed to estimate the curvature and grade at train handling and make-up derailment locations as well as provide a corridor-level context in proximity to these derailments. It was found that the distribution of instantaneous curvature exhibited the most significant changes when comparing train handling and make-up accidents from 2012-2017 to 2018-2023, suggesting that in-train forces on curves might be a focus of mitigations. The presented GIS methodology can similarly be applied to identify temporal and geospatial trends in other geolocated railroad safety events.