Heavy Vehicle National Law changes: what changed on 1 August 2026 and what to check now
The amended Heavy Vehicle National Law adds an Unfit to Drive duty for every heavy vehicle over 4.5 tonnes, raises general mass limits, lets most combinations run to 20 metres, makes several work diary fields optional and replaces NHVAS with a new accreditation scheme over up to three years.
Five rules changed when the amended Heavy Vehicle National Law commenced on 1 August 2026. Line them up and a pattern shows. One adds a duty. Two give vehicles more room. Two reshape paperwork.
The duty is the one to act on first. The new Unfit to Drive duty applies to drivers of all heavy vehicles over 4.5 tonnes, not only fatigue-regulated ones, and it reaches employers and other Chain of Responsibility parties. The room comes from mass and length: General Mass Limits now align with the old Concessional Mass Limits, with tri-axle groups at 21 tonnes, and most combinations other than B-doubles, road trains and vehicle carriers can now run to 20 metres. The paperwork changes are lighter written work diaries and a move from NHVAS to a new accreditation scheme over up to 3 years.
Here at Logistics Industry News we have set out each change below, with what it means for anyone who books, schedules or runs heavy vehicles. Before acting on any of it, confirm with the NHVR how the law applies in your own state or territory.
What changed 1 August 2026: the five Heavy Vehicle National Law changes
| Change | What it means | Key figure |
|---|---|---|
| Unfit to Drive duty | New duty for drivers; reaches Chain of Responsibility parties | heavy vehicles over 4.5 tonnesSource: NHVR |
| Mass limits | General Mass Limits align with old Concessional Mass Limits; CML and 1-Tonne Tri-Axle Mass Transfer Allowance removed | tri-axle group 21 tonnes at GMLSource: NHVR |
| Length | Combinations other than B-double, road train or vehicle carrier | 20 metres (19 m if unbraked heavy trailer condition applies)Source: NHVR |
| Written work diaries | Day of week, standard hours and work/rest totals now optional | No figureSource: NHVR |
| Accreditation | NHVAS replaced by Heavy Vehicle Accreditation | up to 3 years side by sideSource: NHVR |
The law took a while to arrive. Queensland Parliament passed the Amendment Bill 2025 and Amendment Regulations 2025 without amendment on 18 November 2025. Ministers approved the final legislative package in May 2026.
The changes have been in force since 1 August 2026. The transition on accreditation is what keeps this topic current for years, not months.
Who the Unfit to Drive duty covers and what a driver has to do
The rule itself is short. A person must not drive a heavy vehicle on a road while impaired by fatigue or unfit to drive. Fatigue is only part of it. A driver is unfit if they are not of sufficiently good health or fitness to drive safely, whether from a physical or mental condition, a temporary illness, an injury, or the effects of alcohol, drugs or medication.
The duty runs through the whole shift. Drivers must check their fitness before a shift, monitor it during the shift and stop if they become unfit. Yesterday does not count: being fit on the previous shift does not guarantee fitness for the next.
A licence medical does not settle it either. Medical fitness for a heavy vehicle licence does not mean a driver is fit at any given moment, and the duty sits alongside WHS duties rather than replacing them.
If you are building this into your driver programs, our piece on enhancing driver training and development programs is a useful companion.
What freight customers and schedulers must not do under Unfit to Drive
Unfit to Drive: a check for freight customers and schedulers
This is where the duty leaves the cab. Chain of Responsibility parties must make sure their business practices do not cause or encourage someone to drive unfit, and must empower drivers to stop.
The line is clearest at the employer. If a driver says they are unfit, the employer is prohibited under the Primary Duty from requiring them to start or keep driving.
In practice, that means a driver needs a simple way to say "I'm not fit" and a predictable answer when they do. For a business that books freight, it is worth asking how a late delivery is handled when a driver stops, before the day it happens. A booking that only works if nobody ever stops is the kind of practice the duty is aimed at.
How the mass limits changed: CML gone, GML raised
The old two-step system has collapsed into one. General Mass Limits now align with the old Concessional Mass Limits, and both CML and the 1-Tonne Tri-Axle Mass Transfer Allowance were removed on 1 August 2026. A tri-axle group at GML is now permitted 21 tonnes.
Accreditation follows. It is no longer needed to reach CML weights, but operators still need Alternative Compliance Accreditation (Mass) for schemes such as Higher Mass Limits and Performance Based Standards.
For load planning, split your freight into two groups. Loads that sat at CML weights with an accredited carrier now sit inside general limits. Loads that rely on Higher Mass Limits or PBS still depend on your carrier's mass accreditation, so that question has not gone away.
Which combinations can now run to 20 metres
Other combination: a combination other than a B-double, road train or vehicle carrier.
* 19 m if the combination includes a heavy trailer without ADR 38/05-compliant brakes that is not powered by the towing vehicle
The maximum length for a combination other than a B-double, road train or vehicle carrier is 20 metres. It stays 19 metres if the combination includes a heavy trailer that has no ADR 38/05-compliant brakes and is not powered by the towing vehicle. On our reading, that is a 1 metre gain for combinations that meet the brake condition, and none for those that do not.
The other limits on the NHVR's length page: B-double 25 m, road train 53.5 m, vehicle carrier 25 m, articulated bus 18 m. The 20 metre figure is not a B-double figure. This change does not lengthen B-doubles: the length page still lists 25 m, with 26 m only under its stated conditions.
What the Euro VI allowance does, and why it is still settling
Newer trucks get a little help on the front axle. Euro VI (ADR 80/04) vehicles get a mass transfer allowance of up to 0.5 t of the single steer axle limit onto the drive axle group, and that allowance now extends to road trains.
The wording is not settled. The NHVR's current position is that the legislation does not fully reflect the approved policy intent, and the National Transport Commission intends to amend it. Until then, the NHVR said it would enforce in line with the intent: up to 500 kg extra across steer and drive axles, a 315 mm steer tyre if the steer axle is loaded above 6.5 t, and no manufacturer ratings exceeded. Treat that as an interim position, not final law, and check the NHVR's current guidance before relying on it.
What changed in written work diaries, and what still gets checked
| Now optional or no longer required | Still what the regulator looks at |
|---|---|
|
|
| Spelling mistakes do not attract fines. | |
Several fields are gone or optional. In written work diaries, marking the day of the week, marking standard hours and recording work and rest totals are now optional. Drivers also no longer have to return a lost or stolen diary to the NHVR if it turns up.
New stock is coming in slowly. The NHVR says updated written work diaries will become gradually available from August 2026 as existing stock runs out.
Spelling mistakes in a work diary do not attract fines: the regulator looks at the accuracy of the time and location recorded, and the problem arises when it is impossible to tell where a driver stopped.
So the advice for drivers is simple. Spend the care on the clock and the place, not the spelling.
How accreditation moves from NHVAS to HVA
The new Heavy Vehicle Accreditation scheme has two layers. General Safety Accreditation (GSA) is the base tier, and Alternative Compliance Accreditation covers Mass and Fatigue. GSA is a prerequisite for ACA.
Fatigue schemes change name and shape. The Alternative Compliance Hours standard replaces Basic Fatigue Management and Advanced Fatigue Management. Templated tables of hours exist for solo drivers, while two-up operations may need a bespoke table.
Maintenance carries on under a new label, "GSA: Maintenance Assurance Program". It still exempts operators from annual vehicle inspections in applicable states only, which the NHVR's table lists as Queensland and New South Wales.
| Compared | NHVAS | HVA |
|---|---|---|
| What is audited | Selected modules (Mass, Maintenance, Fatigue) | A whole-of-business Safety Management System |
| Audit categories | By module | Five categories (Leadership and Commitment; Risk Management; People; Assurance, Monitoring and Improvement; Safety Systems) |
| Fatigue | BFM / AFM | Alternative Compliance Hours standard |
| Maintenance | Maintenance module | GSA: Maintenance Assurance Program |
The biggest shift is what gets audited. Under NHVAS, audits covered selected modules (Mass, Maintenance, Fatigue). HVA audits a whole-of-business Safety Management System against five categories: Leadership and Commitment, Risk Management, People, Assurance/Monitoring/Improvement, and Safety Systems.
How long the transition runs and when audits fall
- Amendment Bill and Regulations passed without amendment by Queensland Parliament
- Ministers approve final legislative package
- Amended HVNL commences; NHVAS stops accepting new applicants
- NHVAS and HVA run side by side for up to 3 years; operators move on expiry or earlier by choice
Nobody had to switch on day one. NHVAS and HVA run side by side for up to 3 years, and operators move when their current accreditation expires, or earlier if they choose. NHVAS stopped accepting new applicants when the amended law commenced, so a new operator goes straight to HVA.
On our estimate, a carrier that rides out the full transition could still hold NHVAS accreditation until about August 2029: 1 August 2026 plus three years. The NHVR sets the actual cut-off, so check it before relying on that date.
Audits fall late in each period. The NHVR describes one compliance audit per accreditation period, conducted between 9 and 1 month before expiry. New entrants face up to three audits, and the initial compliance audit may be waived.
What to ask your carrier now
Questions for your carrier
For the next few years, two carriers quoting the same job could sit under different schemes. That is normal during the transition. What matters is that each one can tell you where it stands and when it moves.
Start with expiry. A carrier whose NHVAS accreditation expires soon is about to go through HVA, and its audit window opens up to nine months ahead. Then match accreditation to your freight: mass accreditation matters if your loads run at Higher Mass Limits or under PBS, and fatigue accreditation matters if your work relied on BFM or AFM hours.
Finally, ask the Unfit to Drive question out loud. How does a driver tell the carrier they cannot continue, and what happens to your consignment when they do? A clear answer is a good sign.
Have a question about the new law?
If one of these changes touches how you book, schedule or run freight and you want it unpacked further, tell Logistics Industry News what you are working through on our contact page. For anything that turns on your own operation, the NHVR is the authority to confirm it with.
Sources
- https://www.nhvr.gov.au/law-policies/hvnl-reform-implementation
- https://www.nhvr.gov.au/safety-accreditation-compliance/human-factors/unfit-to-drive
- https://www.nhvr.gov.au/road-access/mass-and-dimension/mass-limits/mass-exceptions
- https://www.nhvr.gov.au/road-access/mass-and-dimension/dimension-requirements/length
- https://www.nhvr.gov.au/safety-accreditation-compliance/national-heavy-vehicle-accreditation-scheme/nhvas-transition-to-hva-scheme/changes-to-accreditation
- https://www.nhvr.gov.au/about-us/hvnl
- https://www.nhvr.gov.au/news/2026/07/14/the-nhvr-sets-the-record-straight-on-work-diary-changes-and-the-unfit-to-drive-duty