Heavy vehicle operators working under General Mass Limits (GML) may now load each tri-axle group with up to one tonne more than otherwise permitted, provided the mass limits across the vehicle's non-steer axle groups are decreased by an equivalent amount, and never by more than a one-tonne offset on any of the reduced-limit axle groups.
The new allowance is now in effect across all roads in New South Wales, Tasmania, Victoria, South Australia and the ACT, along with certain declared routes or areas in Queensland (see www.tmr.qld.gov.au for more information). The allowance does not apply to Western Australia or the Northern Territory, which fall outside of the Heavy Vehicle National Law.
The 1TMTA can be applied to heavy vehicle combinations that have a tri-axle group(s) which qualify under GML to be loaded up to 20 tonnes. The allowance cannot be applied under Concessional Mass Limits, Higher Mass Limits, or for any trailers that fall under the Performance Based Standards scheme, unless they've been specifically approved for 1TMTA.
Click here for the NHVR fact sheet regarding the one-tonne mass transfer allowance.