Mass exceptions

There are exceptions under the Heavy Vehicle National Law (HVNL) which provide alternate mass limits when certain other requirements are met.

On this page

Concessional Mass Limits

Concessional Mass Limits (CML) allows operators accredited under the National Heavy Vehicle Accreditation Scheme (NHVAS) to utilise mass limits above the national general limits.

For more information, see Concessional Mass Limits.

Higher Mass Limits

Under the Heavy Vehicle National Law (HVNL), Higher Mass Limits (HML) provides a significant increase in the productivity of road freight transport heavy vehicles by allowing particular vehicles to access additional mass entitlements, subject to conditions.

For more information see Higher Mass Limits

Quad axle group limits

Quad axle group limits (QML) provide semitrailers, B-doubles, and other PBS combinations fitted with quad-axle groups to operate at mass limits up to 27t on a defined road network.

More information can be found on Quad-axle group vehicle combinations.

1-Tonne Tri-Axle Mass Transfer Allowance

The 1-Tonne Tri-Axle Mass Transfer Allowance (1TMTA) provides increased mass limits on tri-axle groups so that they may be operated up to 1 tonne (t) above the tri-axle group 20t GML provided any additional mass loaded onto each tri-axle group is offset onto other non-steer axle or single axle groups.

Euro VI vehicle mass transfer allowance

Euro VI vehicle mass transfer allowance provides up to 0.5t of the single steer axle mas limit to be offset onto the vehicle’s drive axle group.

The MDL Regulation provides mass limits for the following:

  • Euro VI vehicle (complying steer axle)
  • Euro VI vehicle (single steer axle)
  • Euro VI vehicle (twinsteer)

The Euro VI vehicles above must meet the exhaust emissions requirements contained in Australian Design Rule (ADR) 80/04  or later, as well as a number of other requirements as per the MDL Regulation. 

More information can be found in the ADR 80/04 (Euro VI) emissions mass limits increase - Information sheet (PDF, 269KB).

The Department of Infrastructure, Transport, Regional Development, Communications and the Arts has further information on the impact of ADR 80/04 and its health benefits at Questions and answers on the new ADR 80/04.