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III. A and D licence classes and requirements
Size and weight limits for commercial motor vehicles

Commercial motor vehicles are restricted in width to a limit of 2.6 metres (8.5 ft.). Exceptions are made for specialized equipment such as snow removal equipment. In determining the width of a motor vehicle, the mirrors will not be included if they do not extend more than 30 centimetres beyond the vehicle on either side. In regards to the width of a motor vehicle or trailer equipped with auxiliary equipment, it will not be included in the width, provided it does not extend more than 10 centimetres from the side of the vehicle and is not designed or used to carry a load. Semi-trailers are limited to a length of 14.65 metres (48 ft.) or 16.2 metres (53 ft.) if the trailer and tractor meet special requirements.

No combination of vehicles is permitted to exceed a length of 23 metres (75.5 ft.) except double-trailer combinations that meet special requirements for both trailers and the tractor.

All vehicles, including loads are limited to a height of 4.15 metres (13.6 ft.) to ensure adequate clearance is maintained at bridges and overpasses.

You cannot operate a vehicle or combination of vehicles on a highway when its gross weight exceeds the maximum weight permitted under Part VII of the Highway Traffic Act and its regulations.

To determine the gross allowable weight of a commercial vehicle, several factors must be considered, including the number of axles, the size of the tires, the type of suspension, the distance between the axles, the type of load carried (aggregate or non-aggregate load) and the weight allowed on the steering axle.

Several formulas are used to determine the maximum allowable gross weight. These include calculating the sum of the weights allowed on each axle, the registered gross vehicle weight or the weight prescribed in regulations under the Highway Traffic Act. Once these weights have been determined, the lower figure of these is the maximum gross allowable weight.

Drivers, operators and shippers are all responsible for the weight of the commercial vehicle, and any may be charged with an offence.

a tractor-trailer
Diagram 1-2