Semi-quantitative risk assessment of adjacent track accidents on shared-use rail corridors

Safety is a high priority for any rail system, and there are several safety concerns associated with operating passenger and freight trains on shared-use rail corridors. Adjacent track accident (ATA) is one of the most important concerns. ATA refers to train accident scenarios where a derailed equipment intrudes adjacent tracks, causing operation disturbance and potential subsequent train collisions on the adjacent tracks. Other ATA scenarios include collisions between trains on adjacent tracks (raking), turnouts, and railroad crossings. Limited literature is available that addressed the risk of ATA for shared-use rail corridors. The research described in this paper presents a comprehensive risk assessment to identify factors affecting the likelihood and consequence of adjacent track accidents. A discussion on how these factors affect the probability, consequence, and how individual factor relates to each other are provided. A semi-quantitative risk analysis is developed to investigate various factors affecting train accident rate, intrusion rate, and accident consequences. This research intends to depict a high-level overview of adjacent track accidents and provides a basis for future quantitative risk analyses and risk mitigation implementations.