Track Maintenance Reactions for Combined Track Defects

Existing standards in Australia and many other countries determine track maintenance response and train speed restrictions mainly by judging the severity of isolated track defects. However, combined track defects (multiple types of track defects occurring in the same vicinity of a track section) pose greater challenges and risks for train operational safety. And there is a lack of quantifying research in terms of which combinations are the more severe and how maintenance schemes should be adjusted compared with responses to isolated track defects. This study proposed a method to identify severe track defect combinations that pose greater risks for vehicle derailments. A tabular tool was developed to help infrastructure managers to adjust maintenance reactions when track defects are found in combinations.