Mass exceptions

The content on this page includes amendments due to changes to the Heavy Vehicle National Law and Regulations that commenced on 1 August 2026. For more information, please see HVNL reform implementation.

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

On this page

Euro VI vehicle mass transfer allowance

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

Schedule 5B of the Heavy Vehicle (Mass, Dimension and Loading) National Regulation (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.

For more information, see ADR 80/04 (Euro VI) emissions mass limits increase - Information sheet (PDF, 316KB).

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 ADR 80/04.

Higher Mass Limits

Under the Heavy Vehicle National Law (HVNL), Higher Mass Limits (HML) provide 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.

For more information, see Quad-axle group vehicle combinations.

1-Tonne Tri-Axle Mass Transfer Allowance - removed

The 1-Tonne Tri-Axle Mass Transfer Allowance (1TMTA) provided heavy vehicle operators with flexibility in loading certain heavy vehicle combinations by allowing increased mass on tri-axle groups.

The 1TMTA was removed on 1 August 2026 because it was no longer required under the updated mass limit framework. With Concessional Mass Limits (CML) being aligned to General Mass Limits (GML), tri-axle groups operating at GML are permitted a mass limit of 21 tonnes, providing the same operational outcome that was previously achieved through the additional 1-tonne mass transfer allowance. As a result, the 1TMTA became redundant. Its removal simplified the legislation while maintaining operational flexibility and outcomes for operators.

Concessional Mass Limits - removed

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

Concessional Mass Limits (CML) were removed on 1 August 2026 because they are no longer required under the updated mass limit framework. With Concessional Mass Limits (CML) being aligned to General Mass Limits (GML), CML became redundant. Its removal simplified the legislation while maintaining operational flexibility and outcomes for operators.