May 18, 2021

Trucks Down Under: Your Guide to Australian Truck Classifications

Trucks Down Under: Your Guide to Australian Truck Classifications

Do you want to drive a truck down under?
Where kangaroos hop, and drop bears plunder?
Does your engine run, does the diesel thunder?
You’d better count your axles…

In case you hadn’t heard, Fullbay is also operating Down Under. Besides giving us an endless supply of kangaroo-related jokes and an extra reason to watch Outback Truckers, our new adventures in Australia have also given us a chance to learn about how they classify their heavy-duty vehicles.

North Americans reading this, brace yourselves. They use…the metric system.

(Oh, come back here. It’s not that scary.)

For those of you who haven’t run off to hug the Imperial system, we’ve put together this extremely high-level guide to Australian truck classification.


To learn more about how Australia classifies its heavy-duty trucks, we headed to the National Heavy Vehicle Regulator (NHVR), which operates in accordance with the Heavy Vehicle National Law. The law determines how much these vehicles can weigh, how much they can haul, and what size limitations are imposed on each class.

The law defines a heavy vehicle as “a gross vehicle mass (GVM) or aggregate trailer mass (ATM) of more than 4.5 tonnes.” Additionally, each type of vehicle has limits and requirements based around height, length, width, and number of axles, among other things. You can see an insanely detailed breakdown of the regulations and prescribed dimensions in this pamphlet.

Okay. Now that you’ve got some background, let’s move on to the three classes of heavy-duty vehicles. We’ve compiled our lists with the help of this NHVR handout.


To receive a Class 1 Heavy Vehicle rating, a unit and its load “do not comply with a prescribed mass requirement or prescribed dimension requirement applying to it.” It may be a special-purpose or agricultural unit, or it may carry something large that can’t be broken into pieces; think a house.

Real-life examples include “Special Purpose Vehicles” (SPVs) that do something besides hauling freight. Think concrete trucks, tree trimmers, and so on.

Here’s a fuller (but not complete) list:

Agricultural Vehicles

  • Cane Haul-Out Truck
  • Chaser Bin
  • Harvester
  • Grain Auger
  • Tractor

Oversize Overmass Vehicles

  • Block Truck Towing Drawn Platform
  • Two Block Trucks Towing Drawn Platform w/Push Block Truck
  • Prime Mover and Low Loader
  • Prime Mover and Low Loader w/Dolly
  • Prime Mover and Extendable Trailer

Special Purpose Vehicles

  • Cranes (All-Terrain, Pick and Carry, Truck-Mounted)
  • Firetrucks
  • Grader
  • Prime Mover Towing Drill Rig Carrier
  • Truck-Mounted Drill Rig


Class 2 Heavy Vehicles “comply with the prescribed mass requirements and prescribed dimension requirements applying to them.” They are B-doubles, road trains, buses (or articulated buses) and occasionally a vehicle taller than 4.3 meters.

In other words, they’re vehicles built for travel (both human and livestock) and general freight.


  • Controlled Access Bus

Freight Vehicles

  • B-Double
  • A-Double
  • B-Triple
  • AB-Triple
  • A-Triple
  • BAB-Quad
  • ABB-Quad
  • Rigid Truck and 2 Dog Trailers

Performance-Based Standards

  • Prime Mover and Quad Axle Semitrailer
  • Rigid Truck and 5-Axle Semi-Trailer
  • B-Double w/Quad Axle Groups (up to 30m)
  • A-Double (up to 30m)

Vehicles Over 4.3m in Height

  • Vehicle Carrier
  • Livestock Carriers (A-Double and B-triple)


And here we are: the biggest of the big. A Class 3 Heavy Vehicle doesn’t comply with a prescribed mass requirement, and it’s also not a Class 1 Heavy Vehicle.

Real-life examples of this include an underhook/overlift tow truck, which can haul broken-down or inoperable heavy-duty vehicles, or a giant cargo hauler that tops out at over 42.5 tonnes general combination mass.

  • B-Double Towing Converter Dolly
  • Prime Mover and Semitrailer Towing Converter Dolly
  • Rigid Truck and Dog (over 42.5 tonnes)
  • Underhook/Underlift Tow Truck

We hope you’ve enjoyed this little adventure into truck classifications Down Under. If you’re interested in learning more about heavy-duty trucking in Australia, check out some of our resources below!


Suz Baldwin