Classes of heavy vehicles

In relation to access to the road network, the two key types of heavy vehicles are General Access Vehicles and Restricted Access Vehicles. RAVs include Class 1, 2 or 3 vehicles.

General mass and dimension limits

General Mass Limits (GML) apply to all heavy vehicles. The GML state the allowable mass for all types of heavy vehicle axle groups unless the vehicle is operating under an accreditation or an exemption.

Concessional Mass Limits

Concessional Mass Limits (CML) allow an operator to operate at mass limits above the national general limits provided the operator is accredited under the National Heavy Vehicle Accreditation Scheme (NHVAS).

Higher Mass Limits

Higher Mass Limits (HML) allow particular heavy vehicles to access additional mass entitlements providing: operators of vehicles or combinations running HML on tri-axle groups are accredited under the Mass Management Module of the National Heavy Vehicle Accreditation Scheme (NHVAS) ,


A load on a heavy vehicle must be secured to comply with the National Transport Commission’s Load Restraint Guide.