ASSESSMENT OF WET-SNOW BLOCKAGE RISK IN RAILWAY CROSSING FLANGEWAYS FOR MAINTENANCE APPLICATIONS

Abstract

 Railway crossings are among the locations with the highest safety risks under snow and ice conditions, as they represent intersections of rail and road traffic. Wet snow often accumulates in the flangeways of such crossings, significantly increasing the risk of derailment. This study proposes a simple and quantitative method to evaluate this risk. An index termed the estimated blockage height (H_e) is introduced, incorporating correction factors for the snow-to-water ratio, time-dependent densification of wet snow, and the compacting effect of road traffic. The method is applied to past derailment events in Japan using meteorological data from the Automated Meteorological Data Acquisition System (AMeDAS). Results show that the blockage threshold is consistently exceeded during these events, indicating that the proposed approach re-liably reproduces actual incidents. The findings highlight that wet snow has a more severe impact than liquid water because it fills the flangeway with cohesive and dense material, while vehicle traffic accelerates compaction and hinders manual clearing. The formulation is sufficiently simple for practical use in maintenance operations and can be extended to numerical weather prediction data for proactive risk assessment. By quantitatively linking meteorological conditions with the functional vulnerability of flangeways, this study provides practical insights for efficient snow-removal planning and operational decision-making, thereby enhancing railway safety and resilience under wet-snow conditions.