The effect of air temperature on the occurrence of broken and buckled rails

Weather conditions affect many areas of human activity, including rail transport. During periods of low air temperatures, steel rails become brittle and may crack. At high air temperatures, rails extend and may buckle. These incidents negatively affect rail traffic and cause train delays. In Czechia, we identified 8,155 broken and 455 buckled rail incidents over a period of 21 years. 78% of broken rails occurred in winter months (between November and March) and 83% of buckled rails in summer (between June and August). To verify the effect of air temperature on the occurrence of these problems, we built a logistic regression model that included several factors such as air temperature, rail traffic intensity, maximum train speed or railway line geometry. We found that air temperature is an important factor as a 1 °C decrease in minimum daily air temperature (Tmin) increased the odds of a broken rail by 13% and a 1 °C increase in maximum air temperature (Tmax) increased the odds of buckled rails by 38%. The results are particularly relevant regarding climate change. It can be expected that if no measures are taken, with increasing average air temperature, the number of broken rails will decrease in the future, and the number of buckled rails will increase in comparison to the current situation. While the first case can be assessed as a positive change, the second cannot. This trend is also obvious from the data. Between 2013 and 2022, there were on average half as many broken rails as between 2002 and 2012. Buckled rails were then mainly linked to temperature extremes, such as heatwaves in 2006 or 2015. The findings may help rail infrastructure managers or other stakeholders better understand the occurrence of these incidents or may serve as a basis for further research.