OTTAWA, (Oct. 6, 2004) — Transport Canada has published details to the Motor Vehicle Safety Regulations requiring newly manufactured trailers to be equipped with rear impact guards to prevent vehicles from sliding under the rear — also known as “underride” collisions.

As Todaystrucking.com reported last week, the new manufacturing and testing requirements — which will take effect next year — will apply only to newly manufactured trailers with a gross vehicle weight rating of 4,536 kg or more.

Not affected by the amendment are: pole trailers, pulpwood trailers, low-chassis trailers, wheels back trailers, and trailers designed to interact with or having work-performing equipment located in the area that would be occupied by a horizontal member. These trailers are excluded because their design does not permit the installation of a rear guard, their wheels or structure prevent or limit rear underride, or they rarely travel on public roadways.

Also, as in the U.S., trailers that are designed exclusively for the transportation of dangerous goods and that meet the rear impact protection requirements of National Standard of Canada CAN/CSA – B620-98, Highway Tanks and Portable Tanks for the Transportation of Dangerous Goods, are exempt from the energy absorption requirement. Single-unit trucks. Which according to transport Canada are rarely involved in fatal rear-end collisions, are also excluded.

The new manufacturing requirements, as published in the Canada Gazette today, state that the horizontal member of a rear impact guard shall have a cross-sectional vertical height of at least 100 mm at any point across the guard width when installed on a trailer, and the outermost surfaces shall extend outboard to within 100 mm of the longitudinal vertical planes that are tangent to the side extremities, but shall not extend outboard of those planes.

When the trailer is resting on level ground, unloaded, with its full capacity of fuel, its tires inflated and its air suspension pressurized in accordance with the OEMs recommendations, the ground clearance shall not exceed 560 mm at any point across the full width of the horizontal member. However, rounded corners may curve upward within 255 mm of the longitudinal vertical planes that are tangent to the side extremities.

Transport Canada’s research shows that some rear impact guards deformed on impact, allowing the striking vehicle to travel an unsafe distance under the guard and endangering the passengers.

Finally, any height above the ground clearance, the rearmost surface of the horizontal member shall be located as close as possible to a transverse vertical plane tangent to the rear extremity of the trailer, and no more than 305 mm forward of that plane.

The amendment also introduces an attendant test method, also called “Rear Impact Guard,” which sets out the procedure to be used for conducting the required strength and energy absorption tests in order to ensure consistency in testing. The test method allows the rear impact guard to be tested either as installed directly on a trailer or in a test fixture, provided the guard is installed on the test fixture in the same manner as it would be on a trailer.

The government says the energy absorption requirement will help reduce impact forces in a collision, but more important, it ensures that the guard will not sever from the trailer chassis when an equivalent load is applied, giving way to the possibility of passenger compartment intrusion.

However, the Canadian Trucking Alliance expressed concerns over the lack of harmonization of the new standards between Canada and the U.S. “While Canada’s new requirements may provide drivers of small vehicles with the best level of protection anywhere in North America, any safety benefit from the new standards will be diluted unless it is adopted concurrently by Canada and the United States,” said CTA CEO David Bradley in a press release.

In its written submission to Transport Canada in February 2003 CTA stated “To ensure the highest standards of on-road safety, and to create a level playing field for Canadian carriers, CTA would therefore recommend that further discussions take place between Transport Canada and US DOT with a view to developing a single standard — modeled on Transport Canada’s research — applicable in both countries.”

“To my knowledge, the US has made no firm commitment to move forward on under-ride protection in concert with Canada,” added Bradley. “We are concerned by the lack of a North American safety standard and have asked Transport Canada to advise us on the steps the department is taking to foster a harmonized North American approach to underride protection.”