Road transportation of dangerous goods research

From: Transport Canada

This page contains abstracts of research on road transportation of dangerous goods by the Transportation of Dangerous Goods Directorate.

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Abstract - Evaluation of American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XII and National Board Inspection Code requirements for the manufacture and continued service of highway tanks in Canada - December 5, 2023

In North America, a lot of dangerous goods move between Canada and the U.S by road. There are several standards for trucks that are used to transport dangerous goods under pressure (i.e. highway tanks).

In 2016, the U.S. Department of Transportation (US DOT) proposed to reference two additional codes into their current regulation, 49 CFR (also known as Hazardous Materials Regulations):

  • the Code of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME) Section XII
  • the National Board of Boiler and Pressure Vessel Inspector’s National Board Inspection Code (NBIC)

The current regulation in Canada is the Transportation of Dangerous Goods Regulations (TDGR), which references the Canadian Standards Association (CSA) B620 standard. CSA B620 sets out the requirements for design, construction, certification, assembly, modification, repair, testing, inspection, periodic re-testing, maintenance, and marking of highway tanks and TC portable tanks for the transportation of dangerous goods. It currently references ASME Section VIII Division 1, but not the additional codes US DOT is anticipating to include.

As large volumes of dangerous goods are being transported by road between Canada and US, it is important for Canada to ensure ASME Section XII and NBIC requirements provide an equivalent level of safety as the current regulations in Canada.

This study compared the ASME Section XII and NBIC requirements for highway tanks to the existing Canadian regulations and standards. The goal of our project was to identify the differences between the standards.

In general, most of the CSA B620 requirements align with ASME Section XII, NBIC and/or 49 CFR although a small number of differences were noted. Several B620 requirements were not found in the other codes as well as several differences in requirements themselves.

Differences were identified in the following sections of B620-20:

  • Section 5.1.6
  • Sections 5.6.3, 5.6.4, 5.6.6, 5.6.9, 5.6.10
  • Sections 5.2.2, 5.2.4, 5.2.6, 5.2.8
  • Sections 5.7.2, 5.7.4, 5.7.5
  • Sections 5.3.6, 5.3.10
  • Section 5.8.3
  • Section 5.4.7
  • Section 7.2.7
  • Sections 5.5.6, 5.5.7, 5.5.14, 5.5.15
  • Section 8.1.6

The results of this study will help TC look into whether the US requirements provide a similar level of safety to the Canadian requirements

Learn more

To get a copy of the reports, please contact us.

Abstract - Literature review: highway tank vehicle rollovers - December 5, 2023

Transport Canada (TC) has been interested in heavy truck rollovers that involve dangerous goods for a long time. This is because these incidents tend to happen often and can have severe outcomes.

In this study, we asked the National Research Council of Canada (NRC) to review 20 years of research literature and the rules in other jurisdictions (countries or areas of the world) that help to prevent rollovers. The goal of this review was to better understand:

  • the current state of research on reducing the risks of rollovers for highway tank vehicles
  • the relevant regulations in comparable jurisdictions

The review focused on English publications from 2002 to 2022 worldwide that included accident analyses, vehicle models, and safety systems. We also looked at regulations and best practices in North America, Europe, Australia, and New Zealand.

Key findings

  • There were major differences in accident rates between North America and Europe:
    • European countries had lower accident rates compared to Canada and United States
    • this may be because European regulations include a minimum static rollover threshold (SRT), while the North American regulations do not
    • there are still many other differences (size and composition of fleet, infrastructure, etc.), and we still do not fully understand how they could impact the data
  • With the available accident analysis, it was found that highway tanks are involved in more accidents than expected based on how many are on the road compared to other vehicles
  • The research reviewed mainly focused on what constant force is required to roll over a vehicle to understand vehicle performance while moving (like initiating a turn, swerving, or braking):
    • (2) different types of computer models are primarily used to study these effects:
      • computational fluid dynamics (CFD)
      • equivalent mechanical pendulums
    • generally, it was found CFD models offer the most complete and accurate simulation but also require significantly more resources to run them
  • The highway tank industry’s safety systems mainly focus on new types of baffles within the tank, tuned electronic stability control systems, or driver warning systems
  • Some jurisdictions reviewed in this study set a minimum static rollover threshold (SRT) in their regulations. This value is based on the rollover performance in a static test (in other words, raising one side of the vehicle until it tips over) or using a simpler but more conservative calculation method

Gaps identified for future consideration

  • Research done in the 2000s provided excellent background on the state of dangerous good highway tank vehicles on Canadian roads at the time; however, it has not been updated
  • Driver behavior should be a critical factor in highway rollover safety evaluations, but there was limited information on this in the research reviewed
  • There was little research into the dynamic performance (e.g., caused by movement of the fluid inside the tanks) of highway tank vehicles within the Canadian regulatory context. CFD models could be used to help fill this gap
  • More research to shed further light onto the relationship between static rollover threshold and accident rates

Learn more

Full report: Literature review: highway tank vehicle rollovers

Contact us

Safety Research and Analysis Branch
Transportation of Dangerous Goods Directorate
Transport Canada
Email: TC.TDGScientificResearch-RecherchescientifiqueTMD.TC@tc.gc.ca

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