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2 Vehicle exterior

2-2 Dimensions

The vehicle inspector need only inspect dimensions in detail if there is doubt about the vehicle’s compliance.

Reasons for rejection

Mandatory equipment

1. A trailer with a GVM of 3501kg or more exceeds the dimension requirements set out in Table 2-2-3 and is not fitted with the appropriate hazard warning equipment set out in Table 2-2-4.

2. A trailer exceeds the dimensions set out in Table 2-2-3 and is not:

a) a specialist overdimension trailer (Note 1), or

b) a trailer designed primarily to transport an overdimension load, or

c) a trailer operating on a valid permit, exemption or approval.

Note 1 Definitions

Specialist overdimension trailer means a trailer where its primary purpose is to carry out a specialist function that requires overdimension equipment, and the dismantling of the equipment would make it unusable for its intended purpose, or it would take more than four hours to dismantle the equipment.

Caravan trailer means a trailer that is permanently equipped with features intended to make the vehicle suitable as a dwelling place, and must include at least one sleeping berth and one table, both of which may be of a design that allows them to be retracted or folded away.

High-productivity motor vehicle (HPMV) means a heavy motor vehicle or heavy combination vehicle with or without a load:

a) exceeds a gross mass of 44,000kg, or

b) varies from a dimension requirement in Table 2-2-3, (other than width, height or ground clearance), or

c) both (a) and (b), and

d) operates on an HPMV permit issued by a road controlling authority.

Road controlling authority means the authority, body or person having control of the road (eg the NZTA, a regional council or an authorized delegate).

Note 2

An HPMV that does not comply with a dimension requirement in Table 2-2-3 may comply instead with a variation to that requirement as specified on the HPMV permit. The permit must be produced for inspection if required. Any other conditions specified on the permit are not required to be enforced at CoF.

Note 3

An HPMV is not required to comply with the Hazard warning equipment requirements of Table 2-2-4.

Table 2-2-3. Dimension requirements for heavy trailers (see Figure 2-2-9) (Note 2)

Dimension

Maximum distance

Comments

Width

2.55m, or

1.275m from each side of the longitudinal centreline of the vehicle

Measurement does not include:

  • direction indicators and side-marker lamps
  • the bulge towards the bottom of a tyre
  • central tyre inflation system hoses that extend not more than 75mm beyond the outside of the tyre on the drive axles
  • a hubodometer that extends not more than 50mm beyond one side of a vehicle from a non-lifting, non-steering axle whose outer casings are of a light colour, provided the hubodometer is fitted on the axle that causes the least overwidth
  • cameras or close-proximity monitoring systems mounted on the side exterior of a vehicle that extends not more than 70mm from the side wall of the vehicle
  • devices for improving the aerodynamic performance of a vehicle that extend not more than 25mm from either side of a vehicle.

Overall length

11.5m (full trailer, pole trailer)

12.5m (simple trailer)

18m (towing vehicle and semi-trailer with a quad axle-set with two steering axles)

19m (towing vehicle and semi-trailer with  any axle set other than a quad axle-set with two steering axles)

20m (towing vehicle and full trailer (excluding load))

22m (towing vehicle and full trailer (including load if load overhanging the rear of the trailer does not exceed 2.3m in width, or 1.15m from the longitudinal centreline of the vehicle ))

22m (towing vehicle and simple trailer)

20m (any other vehicle combination)

Measurement does not include collapsible mirrors.

Height

4.3m

 

Forward distance

8.5m (full trailer, simple trailer, pole trailer with drawbar at full extension)

9.2m (semi-trailer)

Forward distance is measured from:

  • full trailer: from the rear axis to the front of the trailer body/chassis (excludes drawbar and front axle set with its associated carriage) or load, whichever is foremost
  • simple trailer: from the rear axis to the centre point of attachment to the towing vehicle
  • pole trailer with two axle sets: from the front axis to the centre of the point of attachment to the towing vehicle with the drawbar fully extended.
  • pole trailer with one axle set: from the rear axis to the point of attachment to the towing vehicle with the drawbar fully extended
  • semi-trailer: from the rear axis to the centre of the kingpin

A vehicle with a retractable axle must meet the dimension requirements whether the axle is in contact with the road or in the retracted position.

Rear overhang

4m (for a trailer first registered anywhere before 1 December 1989)

The lesser of 4m or 50% of forward distance (simple trailer, pole trailer with one axle set)

The lesser of 4m or 50% of wheelbase (full trailer, pole trailer with two axle sets)

The lesser of 4.3m or 50% of forward distance (semi-trailer [other than a class TC caravan trailer])

The lesser of 4m or 65% of forward distance (class TC caravan trailer that is a semi-trailer)

Rear overhang is measured from:

  • pole trailer: from the rear axis or centre of bolster to the rear of the vehicle, whichever is the greater.
  • other trailers: from the rear axis to the rear of the vehicle.

A vehicle with a retractable axle must meet the dimension requirements whether the axle is in contact with the road or in the retracted position.

Ground clearance

The greater of 100mm or 6% of the distance from the nearest axle to the point where the ground clearance is measured

Measurement does not include flexible mudflaps, wheels, tyres or devices designed to discharge static electricity.

Front overhang

2.04m radius arc ahead of:

  • kingpin centre (semi-trailer)
  • tow coupling centre (simple trailer)
  • turntable centre (full trailer)
  • turntable centre on towing vehicle (pole trailer)

Front overhang is measured to the foremost point of the trailer (except for full trailer), from the following positions:

  • semi-trailer: centre of kingpin
  • full trailer: centre of turntable to front of trailer body (excludes drawbar)
  • simple trailer: centre of tow coupling
  • pole trailer: centre of turntable on towing vehicle.

Rear trailing unit distance

14.5m (A-train, B-train, towing vehicle and two trailers)

Rear trailing unit distance is measured from the centre of the fifth wheel or tow coupling on the towing vehicle to the rear of the combination.

Articulated vehicle point of attachment

No further rearward than the rearmost axle of the leading trailer

Applies to B-train leading trailer only.

Coupling point distance

30% of forward distance of semi-trailer

  • Applies to A-train only.
  • Measure from the rear axis of the semi-trailer to the tow coupling centre of the full trailer.

Inter-vehicle spacing

4m (between any two consecutive vehicles in a combination)

  • Inter-vehicle spacing is the distance between a towing vehicle (excluding the tow coupling shroud) and trailer (excluding the drawbar or tow rope or front dolly).
  • The inter-vehicle spacing between a towing vehicle and a full trailer must not be less than the greater of 1m or half the width of the foremost point of the trailer (excluding the drawbar and front dolly assembly).

Turning circle

25m outside diameter

  • The vehicle combination must be able to complete a 360 degree turn in either direction.
  • No part of the trailer must encroach outside the outside diameter.
Table 2-2-4. Hazard warning equipment requirements for vehicles that exceed the dimensions in Table 2-2-3 (see Figure 2-2-8 for vehicle category thresholds) (Note 3)

Vehicle category (See Figure 2-2-8)

Dimension

Limits (up to and including)

Required hazard warning equipment

Category 1

Width/forward distance

2.55m /11.4m, or

3.1m/10.5m, or

3.7m/8.5m, or

Flags1 or panels2 fitted on each side at the front and rear as close as practical to the outside edge

Length25m, or
Front overhang 7m, or
Rear overhang7m

Category 2
(not including category 1)

Width/forward distance

2.55m /13.3m, or

4.5m/8.5m, or

1. Panels2 fitted on each side at the front and rear as close as practical to the outside edge

2. OVERSIZE sign3 fitted at the front and rear if more than 3.1m wide

Length35m, or
Front overhang 10m, or
Rear overhang 10m

Category 3
(not including category 2)

Width/forward distance

2.55m /20m

5m/20m

5m/8.5m

1. Panels2 fitted on each side at the front and rear as close as practical to the outside edge

2. OVERSIZE sign3 fitted at the front and rear

Front overhang 10m, or
Rear overhang 10m

Category 4
(not including category 3)

Width/forward distance

11m/20m

11m/8.5m

1. Panels2 fitted on each side at the front and rear as close as practical to the outside edge

2. OVERSIZE sign3 fitted at the front and rear

Front overhang 10m, or
Rear overhang 10m
Category 4BExceeding any limit in Category 4A

1. Panels2 fitted on each side at the front and rear as close as practical to the outside edge

2. OVERSIZE sign3 fitted at the front and rear

3. Revolving amber beacon fitted so that it is visible to approaching traffic if the vehicle is more than 3.7m wide

Note Additional operational requirements may apply, eg if operated at night.

1 Flags:

  • must be fluorescent yellow
  • must be at least 400mm long x 300mm wide.

2 Hazard warning panels:

  • must be reflective yellow-green with a reflective orange diagonal stripe
  • comply with AS/NZS 1906.1:2007
  • be frangible for those portions which extend beyond the vehicle’s limits (frangible means breakable or readily deformable)
  • must be at least of the minimum dimensions and of the colours specified in Figure 2-2-6.

3 OVERSIZE sign:

  • must be black lettering on yellow-green background
  • must be at least 300mm x 1100mm in size
  • be frangible if any part of the sign extends beyond the body or load of the vehicle, whichever it is attached to (frangible means breakable or readily deformable)
  • may be in two parts: OVER and SIZE.
Figure 2-2-6. Hazard panel details

Hazard panels

Figure 2-2-7. Hazard panel location and orientation

5

Figure 2-2-8. Vehicle categories and width/forward distance thresholds.

Use this figure to determine the correct category referred to in Table 2-2-4.
For the purposes of this figure, vehicles with a width less than 2.55m are deemed to have a width of 2.55m and vehicles with a forward distance of less than 8.5m are deemed to have a forward distance of 8.5m

vehicle categories

Figure 2-2-9. Heavy trailer dimensions

HT dimensions

HT dimensions pole trailer

See also to Table 2-2-4.

Summary of legislation

Applicable legislation
Mandatory equipment

1. A trailer with a GVM of 3501kg or more that exceeds the dimensions in Table 2-2-3 must meet the requirements in Table 2-2-4.

2. A trailer with a GVM of 3501kg or more may exceed the dimensions in Table 2-2-3 only if it is:

a) a specialist overdimension trailer (Note 1), or

b) a trailer designed primarily to transport overdimension loads, or

c) a vehicle operating on a valid permit, exemption or approval.

Page amended 1 June 2019 (see amendment details).