Driver Knowledge Tests

What’s a General Access Vehicle vs a Restricted Access Vehicle?

The classifications of heavy vehicles are a confusing mess of specifications and restrictions.

General Access Vehicle

General access vehicles are rigid and combination vehicles that meet a set of standard design requirements, sit within mass and dimension limits, and generally don’t need a permit to operate on roads.

They include:

  • Rigid trucks with 2, 3 or 4 axles, and rigid twin-steer trucks with 4 or 5 axles
  • Semitrailers with up to 6 axles
  • Rigid trucks of 2-4 axles pulling a dog or pig trailer with 2-4 axles.

The mass and dimensions comply with those outlined in the Heavy Vehicle National Law (HVNL) and therefore no heavy vehicle road access permit is required. There may be restrictions to where they can drive based on signage or road conditions.

Maximum dimensions of a General Access Vehicle

Maximum weights are based on the number of axles. For example, while a rigid truck can weigh up to 31 tonnes, this is only for trucks with 5 axles; a 2-axle truck has a maximum mass of 15 tonnes. A detailed list can be found here.

Rigid truck: Length 12.5m, width 2.5m, height 4.3m, mass 31 tonnes

Prime mover and trailer: Length 19m, width 2.5m, height 4.3m, mass 42.5 tonnes

Rigid truck and trailer: Length 19m, width 2.5m, height 4.3m, mass 42.5 tonnes

B-double (prime mover plus semitrailer plus semitrailer): Length 19m, width 2.5m, height 4.3m, mass 42.5 tonnes.

Restricted Access Vehicle

If your vehicle doesn’t meet the specifications above, you have a Restricted Access Vehicle and may need a permit unless you are covered under a notice.


A common notice is for agricultural vehicles. The notice gives a start and expiry date, which vehicles it applies to, a list of the laws, which states it applies in, eligible vehicles, conditions, supporting documents, network and mapping, related notices, resources and definitions. The information is exhaustive with images of the vehicles to avoid confusion.

There may be restrictions on:

  • trip length, for example cotton harvesters in NSW are restricted to 100km per trip.
  • bridge crossings
  • operational hours (e.g. not in school bus hours)
  • maximum width and length
  • motorway and highway use
  • area use (e.g. urban areas)
  • weather restrictions (e.g. not when the surface is wet)
  • speed
  • towing mass ratio

Drivers may or may not need to carry the notice with them.


There are four types of permit.

Class 1 permit

These cover special purpose vehicles (SPV), agricultural vehicles and oversize/overmass (OSOM) vehicles.

Class 2 permit

These cover other B-doubles, road trains, vehicles travelling outside their mass, dimension or operating requirements, and controlled access buses

Class 3 permit

These cover tow trucks, miscellaneous vehicles, mining trailers and commodity scheme

Higher Mass Limits (HML) permit

Higher mass limits cover travel on a road outside the approved HML network.

Darren is an expert on driving and transport, and is a member of the Institute of Advanced Motorists

Posted in Advice