Correct as at 19th April 2024. It may be superseded at any time.
Extract taken: from Vehicle Inspection Portal > VIRMs > In-service certification (WoF and CoF) > Heavy trailers > Vehicle exterior > Dimensions
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, or
d) a vehicle presented with a completed 50MAX proforma entry certification and permit application declaration or HPMV proforma entry certification and permit application declaration signed by a heavy vehicle specialist certifier (Note 4) (Figure 2-2-10).
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.
Note 4
The entry certification and permit application declaration forms can be downloaded from the Waka Kotahi website:
50MAX proforma entry certification and permit application declaration
HPMV proforma entry certification and permit application declaration
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:
|
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:
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:
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:
| Front overhang is measured to the foremost point of the trailer (except for full trailer), from the following positions:
|
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 |
|
Inter-vehicle spacing | 4m (between any two consecutive vehicles in a combination) |
|
Turning circle | 25m 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 |
Length | 25m, or | ||
Front overhang | 7m, or | ||
Rear overhang | 7m | ||
Category 2 | 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 |
Length | 35m, or | ||
Front overhang | 10m, or | ||
Rear overhang | 10m | ||
Category 3 | 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 | 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 4B | Exceeding 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
Figure 2-2-7. Hazard panel location and orientation
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
Figure 2-2-9. Heavy trailer dimensions
See also to Table 2-2-4.
Figure 2-2-10. Sample 50MAX proforma entry certification and permit application declaration and HPMV proforma entry certification and permit application declaration
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).