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On this page:
- Combination or single vehicle
- Trailers
- Refrigerated van trailers
- Livestock carriers
- Trailer drawbars
Combination or single vehicle
The maximum length of a heavy vehicle is:
- for a combination other than a B-double, road train or a vehicle carrier – 19 metres
- for a B-double – 25 metres (see note)
- for a road train – 53.5 metres
- for a vehicle carrier – 25 metres
- for an articulated bus – 18 metres
- for a bus other than an articulated bus – 14.5 metres
- for another vehicle – 12.5 metres.
Note: B-doubles may operate up to 26 metres long if the distance from the front articulation point of the most forward semitrailer to the rear of the B-double is not more than 20.6 metres and the prime mover:
- is fitted with a front under-run protective device and
- for a prime mover manufactured after 31 December 2005 – is fitted with a cab complying with Regulation 29 made under the UNECE Agreement; and
- does not have an area built to carry goods, except for a B-double vehicle carrier.
A prime mover in a B-double carrying, or designed to carry, vehicles may have a deck fitted over the top of the prime mover that is carrying, or built to carry, a vehicle.
More information on how to measure length can be found at VSG37 - Components excluded from vehicle length (PDF, 215KB).
Trailers
On a semitrailer, dog trailer or tag trailer:
- the distance from the front articulation point to the rear overhang line must not be more than 9.5 metres and
- the distance from the front articulation point to the rear of the trailer must not be more than 12.3 metres.
The maximum forward projection of a semitrailer, or anything attached to a semitrailer must not protrude beyond a 1.9-metre arc from the front articulation point.
The front articulation point to the rear of a semitrailer may be up to 13.2 metres if the trailer:
- has a distance of not more than 9.5 metres from the front articulation point to the rear overhang line and
- does not operate in a B-double or road train combination and
- otherwise complies dimensionally.
More information on determining trailer type can be found VSG22 - Requirements for tag trailers (PDF, 319KB) which describes the main types of trailers.
Refrigerated van trailers
The distance from the articulation point to the rear of a semitrailer may be up to 13.6 metres if the trailer:
- is designed and constructed for the positive control of temperature using refrigerated equipment and
- has a distance from the articulation point to the rear overhang line of no more than 9.9 metres and
- does not operate in a B-double or road train combination and
- otherwise complies dimensionally.
Livestock carriers
A trailer built to carry livestock - cattle, horses, pigs or sheep - on two or more partly or completely overlapping decks must not have more than 12.5 metres of its length available to carry livestock.
In a B-double built to carry livestock, the two semitrailers must not have more than 18.8 metres of their combined length available to carry cattle, horses, pigs or sheep.
The length available for the carriage of livestock on a trailer is measured from the inside of the front wall or door of the trailer to the inside of the rear wall or door of the trailer, with any intervening partitions disregarded.
Trailer drawbars
On a dog trailer, the distance between the coupling pivot point on the drawbar and the centre of the front axle group—
- must not be more than 5 metres; and
- if the trailer is used in a road train that is longer than 19 metres—must not be less than 3 metres.
On a trailer, other than a semitrailer or tag trailer, with only 1 axle group, the distance between the coupling pivot point on the drawbar and the centre of the axle group must not be more than 8.5 metres.