Transport Canada takes the safety of commercial vehicles on Canada very seriously. Federal regulations pertaining to commercial buses and heavy trucks under the Canada Motor Vehicle Safety Standards (CMVSS) set requirements on new equipment only relating to such things as brake requirements for trucks and trailers, vehicle lighting systems, tires and underrun barriers. There are no federal regulations relating to after-market items available to the trucking industry.
Transport Canada has no jurisdiction over the inspection of commercial vehicles in Canada. However, under the National Safety Code (NSC), which is a code of minimum performance standards applying to all persons responsible for the safe operation of commercial vehicles, carriers must ensure that their vehicles meet maintenance and performance standards as prescribed in the regulations. On-road inspections of commercial vehicles are typically conducted in compliance with the Commercial Vehicle Safety Alliance (CVSA) roadside inspection requirements.
Matters relating to the vehicle weights and dimensions also falls within the provincial / territorial domain and the enforcement of those laws are within the purview of provincial / territorial law enforcement authorities. There is a Task Force on Vehicle Weights and Dimension mandated to improve uniformity in regulations governing the weights and dimensions of commercial vehicles operating between provinces and territories.