Sign Standards for Heavy Vehicles
Heavy vehicle guide
Which signs does my vehicle need?
It comes down to three things: how heavy the vehicle is, how long the combination is, and how wide the load is.
Quick answer
- Truck over 12 t GVM or trailer over 10 t: rear marker plates
- Combination over 22 m, up to 30 m: LONG VEHICLE sign at the rear
- Combination over 30 m: ROAD TRAIN signs front and rear
- Oversize, wider than 2.5 m or longer than 25 m: OVERSIZE signs front and rear, plus flags
- Placard load of dangerous goods: class labels and EIPs
Sign by sign
| Sign | Required when | Fitted | Shop |
|---|---|---|---|
| Rear marker plates | Motor vehicles over 12 t GVM, trailers over 10 t GTM, and most buses over 12 t GVM (VSB12) | Rear, preferably 400–1500 mm off the ground (max 2000 mm), within 500 mm of the outer edge | Rear markers |
| Do Not Overtake Turning Vehicle | Vehicles or combinations 7.5 m or longer that need to straddle lanes to turn. Must not be fitted under 7.5 m. | Rear, left-hand side (or as part of a 34A plate) | Rear markers |
| LONG VEHICLE | Combination over 22 m, up to 30 m | Rear | Long Vehicle |
| ROAD TRAIN | Combination over 30 m | Front and rear | Road Train |
| OVERSIZE | Over 2.5 m wide or over 25 m long | Front and rear | Oversize |
| OVERSIZE (rear only) | Up to 2.5 m wide, over 22 m and up to 25 m long | Rear | Oversize |
| Warning flags | Over 2.5 m wide or over 25 m long | Each corner, 450 x 450 mm minimum | Flags |
Rear marker plates: check this
- Plates must be Class 400, Class 1A or UNECE R70, and all plates on one vehicle must be the same class. Our plates are Class 400.
- Class 2 plates are being phased out: none can be newly fitted since 31 December 2020, so replace worn ones with Class 400.
- Prime movers, lead semi-trailers and converter dollies use the 615 strip plates (within 200 mm of the outer edge).
- Don’t cut or drill plates. Strip plates can be trimmed, but no more than 10 mm.
- The NHVR also recognises conspicuity markings fitted to the Australian Design Rules as an alternative to plates on some vehicles. See conspicuity tape.
Where rear marker plates go
Diagram based on NHVR VSB12.
Fitting LONG VEHICLE and ROAD TRAIN signs
- Bottom edge at least 500 mm off the ground, top edge no higher than 1.8 m.
- Horizontal, fully visible, and fixed so it can’t flap, fold or warp.
- Two-part signs read LONG | VEHICLE or ROAD | TRAIN, mounted at the same height.
- Banner (flexible) signs are allowed.
Why it matters: a vehicle that doesn’t meet the vehicle standards counts as defective. That can mean an on-the-spot fine, a defect notice or prosecution.
Operating in WA or the NT? They run their own rules. Standard signs are still accepted in WA. See state differences.
Sources: NHVR · NHVR VSG-19 · NHVR Schedule 8 · NHVR VSB12 v2.3 (Nov 2025) · RoadRanger catalogue
General information to help you choose signs, not legal advice. Your notice, permit or order conditions take priority. Not sure? Ask Randy or contact the team.