Amendments to the Heavy Vehicle National Law (HVNL) passed Parliament in November 2025 and commenced on 1 August 2026.

The reform package, which includes the Heavy Vehicle National Law Amendment Act 2025 (the Amendment Act) and the Heavy Vehicle National Law Amendment Regulation 2026, brings significant changes aimed at improving the administration and efficiency of the heavy vehicle industry and the safety of heavy vehicle drivers and road users alike.

In our previous article, we explored the new accreditation framework and requirements for operators, drivers and others who work for heavy vehicle operations. In this article we look at the expanded driver duty, key changes to the Heavy Vehicle (Mass, Dimension and Loading) National Regulation (the MDL Regulation), the shift from the HVNL to National Regulations for some requirements and other important regulatory changes.

Contents

  1. The expanded driver duty
  2. Changes to mass, dimension and loading requirements
  3. The shift from the HVNL to national regulation
  4. New written work diary requirements, codes of practice framework and strengthened enforcement powers
  5. Keep your compliance on track with Environment Essentials

The expanded driver duty

Under the previous legislation, drivers had a duty to not drive a fatigue-regulated heavy vehicle, which is over 12 tonnes (t), if they were impaired by fatigue.

These legislation changes extend this duty to apply to all heavy vehicles over 4.5t and combines it with an additional duty to be ‘fit to drive’. A driver is considered ‘unfit to drive’ if at that time, they are not of sufficiently good health or fitness to drive the vehicle safely, either due to physical or mental conditions, temporary illness or the effects of alcohol and other drugs.

As part of this expanded duty, drivers are required to ensure they are fit to drive before starting to drive, not start driving if they are unfit, actively monitor their fitness to drive during a shift and take actions to ensure they are fit to drive before resuming their next shift.

Chain of Responsibility (CoR) parties are also required to ensure business activities do not cause or encourage a driver to drive if unfit and must provide an opportunity for the driver to stop driving when necessary.

Breach of this duty incurs an increased maximum penalty of $20,000, up from $6,000.

Changes to mass, dimension and loading requirements

In an effort to boost productivity, reflect modern configurations and maintain safe performance in the heavy vehicle industry, the following changes to the Heavy Vehicle (Mass, Dimension and Loading) National Regulation (MDL Regulation) have been made:

The increase of General Mass Limits (GML) to match limits under Concessional Mass Limits (CML)

  • The axle mass limits for tandem axle groups and tri-axle groups increase to match their current CML equivalents, and the axle mass limits for quad-axle groups and groups of five or more axles also increase. Bus axle group limits are retained.
  • Tandem axle groups have a maximum mass limit of 17t and tri-axle, quad-axle and groups of five or more axles have a maximum mass limit of 21t.
  • Overall mass increase limits are capped at 1t for heavy vehicles with a combination mass of less than 55t, and 2t for those with more than 55t.
  • Increased maximum masses for previously excluded vehicle types, such as truck and pig combinations and Class 1 vehicles, are also granted.
  • The existing CMLs are repealed.

The increase of vehicle length limits

  • The length limit for general access vehicles and combinations increases from 19m to 20m.
  • Heavy trailers in a 20m combination must be fitted and compliant with the latest braking technology (ADR 38/05 or later) and have the braking system powered by the towing vehicle.
  • The maximum distance from the front articulation point to the rear overhang line of 20m semi-trailer, dog trailer and tag trailer combinations increases to 10.5m, and the maximum distance from the front articulation point to the rear increases to 14.5m.
  • Semi-trailer combinations with a front articulation point to the rear overhang line of more than 9.5m must be fitted with ADR106/00 (or later) compliant side underrun protection.
  • The maximum rear overhang limit of semi-trailer combinations increases to 4.0m.

The incorporation of Euro VI compliant prime movers into road train combinations

  • Road trains with a Euro VI compliant prime mover can access the 0.5t steer axle mass increase but are restricted to a maximum of 7.0t.
  • The steer axle of eligible primer movers is required to have tyres fitted with a section width of at least 315mm.
  • Euro VI compliant prime movers with a twin steer axle group can also access the 0.5t steer axle mass increase, with a maximum of 11.5t. This combination is also required to have tyres fitted with a section width of 275mm and be fitted with a load-sharing suspension system.

The amendment of tow mass ratio and associated tag trailer conditions

  • The existing tow mass ratio requirement of 1:1 for a heavy vehicle towing a tag trailer is replaced with a new tow mass ratio of 1:1.3.
  • A new requirement for the steer axle mass to be the greater of at least 20% of the truck’s Gross Vehicle Mass or the manufacturer’s minimum requirement are introduced.

The transfer of requirements from the current HVNL

Certain requirements relating to the definition of twin steer axle group, the display of warning signs and class 2 heavy vehicle authorisation (permits) and mass or dimension exemption permits have moved from the previous HVNL into the MDL Regulation.


The shift from HVNL to national regulation

Other prescriptive detail that is was previously enforced under the HVNL has been transferred to the Heavy Vehicle (General) National Regulation, Heavy Vehicle (Fatigue Management) National Regulation and Heavy Vehicle (Vehicle Standards) National Regulation.

This shift aims to simplify the law and allow for the regulatory framework to better adapt to future technologies or industry needs. The transferred requirements relate to the following matters, among others –

Heavy Vehicle (General) National Regulation

  • What the National Heavy Vehicle Regulator (NHVR) must consider when assessing a Performance Based Standards (PBS) design approval application and PBS vehicle approval application.
  • The requirement for a driver to keep a copy of the PBS vehicle approval.
  • Provisions related to exemption (permits) and authorisation (permits) including amendment, suspension and cancellation, among other things.

Heavy Vehicle (Fatigue Management) National Regulation

  • How work and rest time is counted in 15-minute periods in written or electronic work diaries.
  • How information must be recorded in a work diary.
  • Provisions related to the form, application and issue of a written work diary.
  • Requirements relating to fatigue record keeping exemption (permits), work and rest hours exemption (permits) and work diary exemption (permits).

Heavy Vehicle (Vehicle Standards) National Regulation

  • The circumstances in which the requirement to comply with heavy vehicle standards does not apply.
  • The circumstances in which the NHVR can grant a vehicle standards exemption (notice).
  • Requirements for approval of heavy vehicle modification, or use of a modified heavy vehicle.
  • The offence for tampering with a heavy vehicle plate or label.
  • Requirements related to vehicle standards exemption (permits).


New written work diary requirements, codes of practice framework and strengthened enforcement powers

Other changes from this reform update certain requirements relating to completing Written Work Diaries (WWD), Codes of Practice (CoPs) and powers. For example:

  • A new version (v1.4) of the WWD is available, reflecting the changes to the HVNL such as a new checkbox under the Driver Hours Options section for Alternative Compliance Hours.
  • Drivers can continue to use their existing WWD however it must be completed in accordance with the new HVNL requirements.
  • A new CoP framework will replace the existing industry CoP framework to support and guide CoR parties and drivers to meet their heavy vehicle duties and obligations. The NHVR will be responsible for issuing, amending and revoking CoPs.
  • New powers are introduced for Responsible Ministers to issue directions to the NHVR relating to preventing and minimising serious public risk, acting in relation to Alternative Compliance Accreditation, and investigating or providing advice or information.
  • The issue of an improvement notice concurrent with a prosecution for the same conduct will be allowed, provided the offence is deemed serious enough and there is sufficient evidence.
  • Where suitable, authorised officers can issue formal warnings instead of fines, and there will be a wider range of breaches for which formal warnings may be issued.
  • Courts can deliver alternative verdicts for primary duty offences.
  • A number of penalty amounts have changed and several offences consolidated.


Keeping your compliance on track with Environment Essentials

These amendments will be summarised and incorporated into our health and safety online directory, SafetyLaw, from the 14th August 2026.

These detailed and easy-to-read summaries can be integrated into your processes, policies and procedures, used for internal compliance evaluations or as an aid to cultivate understanding and compliance among employees.

Our complimentary news service, HSE Bulletin, will also notify you of additional developments.

If you are an Environment Essentials subscriber and would like to add SafetyLaw to your cache of products, please contact your Account Manager or our client services team.

If you are not an Environment Essentials subscriber but would like to stay on top of the heavy vehicle reform and identify, understand and integrate your heavy vehicle requirements, then sign up for a free trial today or get in touch with our sales team.

For a bit more horsepower, including a list of all penalty changes, request our eBook – Unpacking the Heavy Vehicle National Law reform.

Email info@enviroessentials.com.au for your copy today.

References

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