Mass & Dimension: Changes to Heavy Vehicle National Law

From 1 August 2026, prescribed general access mass and vehicle length limits changed under the amended Mass, Dimension and Loading (MDL) Regulations, following the implementation of the Heavy Vehicle National Law Amendment Bill 2025.

For the industry, these changes are likely to be positive from a productivity perspective, but benefits will vary considerably by truck configuration, quarry-to-customer route and whether the operator is already using Concessional Mass Limits (CML), Higher Mass Limits (HML) or Performance-Based Standards (PBL).

Changes come into effect from August

The proposed changes will:

• Increase General Mass Limits (GML) to align with the current Concessional Mass Limits (CML)
• Expand Euro VI concessions to include road trains.
• Increase the length limit for vehicles from 19 metres to 20 metres if requirements are met. (Note: B-doubles are not included in the current regulations but will be considered in future regulatory amendments).
• Amend the tow mass ratio and associated conditions for tag trailers.

The biggest practical benefit is that a quarry truck was previously constrained by the old General Mass Limit (GML), can potentially carry another tonne of aggregate per trip without moving into a CML arrangement.

More information
Visit the NHVR website