Changed 1 August 2026
The unfit to drive duty, in plain English. It now reaches every heavy vehicle over 4.5 tonnes — and it is not only your duty.
On 1 August 2026 the Heavy Vehicle National Law picked up a duty about being fit to drive — not just rested, fit. Fatigue was already in there. What is new is that everything else about your condition is in there with it, and it now reaches a lot further down the weight scale than it used to.
You must not drive a heavy vehicle on a road while “impaired by fatigue or unfit to drive”.How the NHVR states the duty
The big change
The fatigue rules used to reach fatigue-regulated heavy vehicles, which in practice meant over 12 tonnes. This duty starts at 4.5 tonnes. If you drive a tipper, a tow truck, a rigid on local work, a bus, a crane truck, a furniture truck — anything over four and a half tonnes — you are in it now, and plenty of blokes in that bracket have never had to think about any of this before.
Worth knowing: this is not the medical you do for your licence. That is a separate thing and it has not changed. This is about your condition on the day, for the shift you are about to start.
What counts
It is not only grog and not sleeping. The NHVR’s own guidance covers:
Read that list again and you will notice most of it is ordinary life. Having one of these things is not an offence. Driving while one of them is affecting how you drive is the problem.
Your end of it
Check before you start
Be fit to drive before the shift begins, not two hours into it.
Do not start if you are not
If something is affecting you, the duty says do not commence. For any reason, not just fatigue.
Keep an eye on yourself along the way
You can be fine at loading and not fine at three in the morning. The duty runs for the whole trip.
Stop if it changes
If you become unfit during the shift, you stop. That is the expectation written into it.
Sort it before you go back
Take whatever action it needs — rest, a doctor, a change of medication — before the next one.
Hours are not sleep
A work diary records time off. It does not record sleep. Seven hours in the book can be forty minutes finding a bay, a feed, a shower, a phone call home, and four hours of actual sleep with a reefer running beside you. The book says you are compliant. It has no column for whether you slept.
The duty asks whether you are fit. Not whether you are legal. You can be inside every line in that book and still be unfit to drive, and the book is not a defence.
The rest requirements are the least you can take. They are not a measure of what you need, and nothing stops you taking more.
The other number — the delivery window — is not law at all. It is a customer’s preference. It gets moved for a breakdown, a flat, a road closure and a wet pit. It can be moved for a driver who is not fit to drive.
So take the sleep you actually need, and let the window move. Since 1 August that is not you being difficult. That is the duty working the way it was written, and the people who built the schedule carry it alongside you.
The part that protects you
This is the half that gets left out when it gets explained to drivers, and it is the half worth knowing. Everyone else in the chain carries it too — operators, schedulers, consignors, the people setting the run times.
They must not cause or encourage you to drive while you are unfit, directly or indirectly. And when you do stop, they are expected to support that, not make you wear it.
So the ring-around that pressures a crook driver back behind the wheel is now their exposure, not just yours. If you stop because you are not fit and it turns into a problem for you, that is worth talking through before you accept it — take it to Legal Matters.
Straight up
Plenty of drivers looked at this and saw one more thing to be done for. Fair enough. But read who it lands on: the duty not to push a driver out crook sits with the people doing the pushing, and the penalties on that side went up when this came in.
The thing that actually puts you in trouble is driving when you know you should not have, and saying nothing. The thing that keeps you out of it is saying something early — which most of us were raised not to do.
The source
We are drivers, not lawyers, and the wording of the law matters more than our summary of it. The regulator’s own guidance is free and it is not hard to read:
This page is general information about a change in the law. It is not legal advice, it does not know your circumstances, and it is not a defence. If you have had a notice over this, or you have been stood down for stopping, talk to a qualified professional — and bring it to the group while you are at it.
Take it further
