Frequently asked questions about mass, dimension and loading.
Am I restricted to certain routes if operating within CML?
Operators operating at Concessional Mass Limits (CML) have access to the same network that their particular vehicle class is permitted to operate under General Mass Limits, except where prohibited by a load limit specified for a road, bridge or causeway by a sign or notice.
See our Concessional Mass Limits page for more information.
Do I need certified road friendly suspension if I am operating under CML?
No, but operating under Concessional Mass Limits (CML) requires the operator and vehicle to be enrolled under the NHVAS Mass Management module and it is a requirement of this scheme that you ensure the suspension is maintained.
Before operating at CML, we strongly recommend you check relevant notices to the jurisdiction you will be operating in to ensure that you conform to potential minor variations from the national policy.
See our Concessional Mass Limits page for more information.
Do I need Intelligent Access Program (IAP) tracking for HML?
For access to QLD and NSW HML routes you will need a certified tracking system fitted to the vehicle. In SA you require IAP if you do not complete and carry a HML route compliance certificate.
See Intelligent Access Program for more information.
Do I need road friendly suspension for HML?
Yes. See Higher Mass Limits page for more information.
What are the mass limits set out under HML?
The following axle mass limit increases apply for vehicles fitted with road-friendly suspensions operating at Higher Mass Limits (HML):
- 0.5 tonne increase on tandem axle groups to 17 tonnes
- 2.5 tonne increase on tri-axle groups to 22.5 tonnes
- 1 tonne increase on single drive axles on buses to 10 tonnes
- 1 tonne increase on six-tyred tandem axles to 14 tonnes.
Before operating under HML, we strongly recommended you check the HML transition notice relevant to the jurisdiction you will be operating in to ensure that you conform to potential minor variations from the national policy.
See Higher Mass Limits for further information.
What limits are permitted under CML for my type of heavy vehicle?
Under Concessional Mass Limits, the Gross Vehicle Mass of vehicles with tandem and tri-axle groups are set at 5% above General Mass Limits (GML), subject to:
- a maximum increase of 1 tonne for a vehicle or vehicle combination with an allowable gross vehicle mass not exceeding 55 tonnes (e.g.: 6-axle semi-trailer)
- a maximum increase of 2 tonnes for vehicle combinations with an allowable gross vehicle mass exceeding 55 tonnes (e.g.: 9-axle B-Double)
- an upper limit on axle and axle group mass as given in the table of Concessional Mass Limits.
Note: In Queensland, as a means of providing more flexibility to operators, the mass limits that apply in CML are extended to include the following mass limit increases:
- In Queensland a maximum increase of 3 tonnes for vehicle combinations with an allowable gross mass exceeding 85 tonnes but not exceeding 120 tonnes
- In Queensland a maximum increase of 4 tonnes for vehicle combinations with an allowable gross mass exceeding 120 tonnes.
See our Concessional Mass Limits page for more information.
Where can I obtain a list of mass limits applicable to heavy vehicles?
A comprehensive list of the mass limits under the HVNL can be found on our General mass and dimension limits page.