Highway Tank Rollover Incident Analysis

Highway tank rollover accidents involving dangerous goods are hazardous events for which the consequences can be severe, and efforts must be taken to reduce their frequency of occurrence. Previous research completed by TC contained in the report Highway Tank Vehicle Rollover – Literature Review provided a review of the current research, as well as technologies that are used to reduce the risk of highway tank rollovers, and an international scan to identify regulatory requirements aimed at reducing rollovers in other jurisdictions (i.e., North America, Europe, Australia, and New Zealand). As part of the first phase project results, it was noted that European countries have much lower rollover rates compared to Canada and the United States of America (USA). A common element across most jurisdictions, excluding North America, is regulatory requirements that set a minimum static rollover threshold (SRT). This threshold can be based on the actual rollover performance of a highway tank in a static test or calculated using a simpler and more conservative theoretical method. There is a possibility that these minimum SRT requirements contribute to the favourable differences in accident rates in Europe as compared to North America. This previous work has prompted TC to investigate whether a minimum SRT should be introduced in Canada for transportation of dangerous goods. To aid in determining the best path forward, it is important to analyse recent incident data related to dangerous goods highway tank vehicle in Canada, particularly in rollover situations and if there are trends that could be attributed to SRT. The objective of this study is to perform an analysis on accident data related to highway tanks transporting dangerous goods on North American roads between the period 2014-2024, in an effort to understand why rollover rates are higher in Canada and the USA than in the other countries previously studied and to gain an understanding of how a minimum SRT value could be used to reduce these incidents in Canada.