A transnational statistical approach on quantifying root causes of railway squats and predicting squat risk

Squats on rails are a major contributor to maintenance costs in modern railway systems, yet their root causes and varying prevalence between networks are not fully understood. This study presents a harmonised statistical framework that enables international comparison of railway systems and quantifies squat risk and its influencing factors using a Cox proportional hazards model. The methodology is applied to data from the DACH region (Germany, Austria, Switzerland), considering parameters from railway operation, infrastructure management and track monitoring. Results show that the combination of low freight shares, low daily loads and hard rail grades in straight track most significantly increases squat risk. Predicted squat probabilities differ systematically between networks, with OEBB showing the lowest and SBB the highest values. The proposed model enables squat risk estimation based on five widely available input parameters and provides insights to support the optimisation of maintenance efforts and long-term system design.