Truck and trailer rules in British Columbia: trailer brakes, size limits and commercial vehicle licensing
What British Columbia's Motor Vehicle Act Regulations and Commercial Transport Regulations say about trailer brakes at 1,400 kg, automatic brake application on a breakaway, the 2.6 m width and 4.15 m height limits, length limits, and how commercial vehicles are licensed by weight.
Checked against the sources at the bottom of this page on October 8, 2026. Rules, fees and pay change: the source has the last word.
This page reports what the official source says. It is not legal advice: ask the office named here. All of the sources are British Columbia law published on the BC Laws website: the Motor Vehicle Act Regulations, the Commercial Transport Regulations and the Commercial Transport Act. Federal background and the other places are on the parent page, trucks and trailers for tree work. British Columbia writes its limits in metric units, and this page keeps them.
At a glance
| Item | What the sources say |
|---|---|
| Trailer brakes | Brakes at each end of each axle, except a trailer of 1,400 kg licensed weight or less that is under 50 percent of the towing vehicle's licensed weight |
| Driver-applied brakes | Required where the trailer's licensed weight is over 2,800 kg |
| Breakaway | A commercial trailer's service brakes apply automatically on separation and stay applied for at least 15 minutes |
| Width, height | 2.6 m wide; 4.15 m high; both without a permit |
| Length without a permit | 12.5 m single vehicle; 20 m combination with one articulation point; 23 m with more than one |
| Commercial vehicle | Registered and licensed with the Insurance Corporation of British Columbia by weight |
| Licence class by weight | Not published on the pages read |
| Carrier number | Not published on the pages read |
Trailer brakes
Section 5.02 of the Motor Vehicle Act Regulations says a trailer must have brakes at each end of each axle. Brakes are not required on any axle of a trailer, other than a towing dolly, whose licensed vehicle weight is 1,400 kg or less and is less than 50 percent of the licensed vehicle weight of the vehicle towing it. Other exceptions cover a house trailer with more than two axles, a towing dolly in listed cases, and a trailer that is a piece of construction machinery towed by a truck with a heavier rating than the two together. Where a trailer's licensed vehicle weight is over 2,800 kg, its brakes must be capable of being applied by the driver of the towing vehicle from the normal seated position. The same section sets stopping distances from 30 km/h: 8 m for a passenger vehicle built for not more than 9 people, 9 m for a single vehicle rated under 4,600 kg, 12 m for other single vehicles, and 15 m for most combinations. Section 5.03 requires a parking brake or emergency system that will alone stop and hold the vehicle or combination, and bars leaving a detached trailer on a highway unless its wheels are locked.
Division 6 covers buses, trucks, truck tractors and commercial trailers, where a commercial trailer is a trailer with a gross weight of more than 1,400 kg. Section 6.06 requires a service brake on each wheel of those vehicles, with listed exceptions. Section 6.07 requires a commercial trailer's service brakes to apply automatically if the trailer separates from the towing vehicle and to stay fully applied for at least 15 minutes, and requires a truck towing a braked commercial trailer to have a means so that its own service brakes still work enough to stop it in a breakaway. The pages read do not mention safety chains. See Division 5 of the Motor Vehicle Act Regulations on brakes and Division 6 on truck and trailer brakes.
Width, height and length
Section 7.06 of the Commercial Transport Regulations says a person must not, without a permit, operate a vehicle with a total outside width over 2.6 m. Mirrors, within limits, and auxiliary equipment that does not carry cargo and sticks out no more than 10 cm a side are left out of that width. Section 7.05 sets the height limit at 4.15 m without a permit, and a height posted on a low-clearance warning sign applies as well. For length, section 7.08 sends the reader to the dimension tables in the appendices of the regulation and adds general limits without a permit: a single vehicle over 12.5 m, a trailer over 12.5 m, a combination with one articulation point over 20 m, a combination with more than one articulation point over 23 m, and a combination measured from the kingpin to the rearmost point of the trailer over 14.65 m. Equipment such as air connectors, ladders and load securement devices that does not carry cargo is left out when length is measured, within the distances the section gives. See the Commercial Transport Regulations.
Licensing a commercial vehicle
The Commercial Transport Act defines a commercial vehicle to include a motor vehicle with a permanently attached truck or delivery body, a combination of vehicles, and a road building machine. It also defines a trailer as a vehicle without motive power drawn by a motor vehicle, and leaves out a trailer under 1,401 kg gross vehicle weight licensed under the Motor Vehicle Act. Section 6 requires the owner of a commercial vehicle, trailer or semi-trailer to register it with the Insurance Corporation of British Columbia, obtain a licence for its operation and insure it before it is used on a highway. The licensed gross vehicle weight for most commercial vehicles is the unladen weight plus half of that weight, or the gross weight the applicant declares, whichever is greater, up to the legal maximum. A commercial vehicle registered outside the province can get a permit for up to 30 consecutive days, with a limit of two permits per vehicle in each licence year, for a single trip into or through the province. The Commercial Transport Regulations add a non-resident permit for a 3 month period, usable for movement within the province only for a vehicle with a licensed gross vehicle weight of less than 11,794 kg. See the Commercial Transport Act.