What are General Mass Limits?
Short answer
General Mass Limits are the default axle-group and gross-mass limits for heavy vehicles unless a lawful exception, exemption, notice, permit, HML entitlement or PBS approval applies.
Plain English
GML starts with the legal limit for each axle or axle group, including 17.0 tonnes for a qualifying dual-tyred tandem axle group and 21.0 tonnes for a qualifying dual-tyred tri-axle group. The vehicle’s gross limit also depends on axle spacing, vehicle configuration and manufacturer ratings.
What this means operationally
Load plans must satisfy every applicable axle, axle-group, gross, axle-spacing and manufacturer limit. The current reduced-mass-amount mechanism must be applied exactly as prescribed and should not be treated as a target loading margin.
Who it applies to
Most heavy vehicles operating at general mass in an HVNL jurisdiction, including operators, drivers, loaders, loading managers, consignors and others who influence the vehicle’s mass.
Example
A standard semitrailer may be within its overall gross figure but still breach GML if an individual axle group is overloaded or a lower manufacturer rating applies.
Exceptions and traps
HML, PBS, a mass exemption, notice or permit may authorise a different limit. Manufacturer ratings and other safety or dimension requirements can impose a lower practical ceiling.
What changed
From 1 August 2026, Concessional Mass Limits were removed and GML increased to the former concessional levels. For a non-bus vehicle or combination, the prescribed reduced mass amount can be up to 1 tonne where that amount is 55 tonnes or less, or up to 2 tonnes where it is more than 55 tonnes, subject to the detailed regulation.
Previous rule
Before 1 August 2026, CML operated as a separate concession above the former GML values for eligible vehicles and operators.
Legal foundation
Heavy Vehicle (Mass, Dimension and Loading) National Regulation 2013, Sch 1 and prescribed mass requirements
Sources & primary documents
- www.legislation.qld.gov.au/view/whole/html/inforce/current/sl-2013-0077
- www.nhvr.gov.au/road-access/mass-and-dimension/mass-limits/general-mass-limits
- www.nhvr.gov.au/road-access/mass-and-dimension/mass-limits/mass-exceptions
- www.nhvr.gov.au/document/863
WWTG verification: Queensland legislation, NHVR
Frequently asked questions
What is GML?
It is the default legal mass framework for heavy-vehicle axles, axle groups and gross mass unless another lawful entitlement applies.
What is the GML for a dual-tyred tandem axle group?
For the qualifying axle-group category in the current table, it is 17.0 tonnes.
What is the GML for a dual-tyred tri-axle group?
For the qualifying axle-group category in the current table, it is 21.0 tonnes.
Do CML still exist?
No. CML were removed on 1 August 2026 when GML increased to the former concessional levels.
Can I load to the stated gross figure without checking axles?
No. Every axle and axle-group limit, axle spacing, manufacturer rating and other requirement must also be satisfied.