NSW changes driving rules for medicinal cannabis patients

For years, Australian patients prescribed medicinal cannabis for pain, anxiety, sleep, or other conditions have faced an unresolved contradiction. Their treatment was legal. Their test result at a roadside check was not.

NSW has just changed that. The Road Transport Amendment (Medical Cannabis and Driving Offences) Act 2026 repeals the automatic three-month licence suspension that applied to any driver who returned a positive THC result at roadside testing, regardless of impairment. Under the new law, registered medicinal cannabis patients can drive legally with THC present in their system — if they meet specific conditions.

This is the first change of its kind in Australian driving law. It is also, for GPs who prescribe medicinal cannabis, an immediate context shift for the prescribing conversation about practical consequences of a cannabis script.

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What the new law actually says

The conditions are specific:

• The patient must hold an unrestricted licence. Learners, P-plate drivers, and commercial vehicle operators are excluded entirely.
• The patient must register with Transport for NSW, providing evidence of a valid prescription.
• The patient must complete a mandatory online education module on cannabis and driving safety.
• No alcohol or other drugs may be present when driving.
• Roadside testing still applies — a positive THC result triggers a 24-hour driving ban.
• Penalties apply only if a laboratory test confirms THC above 50 ng/ml after a second offence within two years.

The law is expected to take effect in late 2026 or early 2027, with a one-year review period built in.

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Both sides of this

The case for the change is straightforward. THC is fat-soluble and detectable in saliva for days to weeks after use — particularly in regular users. A patient who took their prescribed dose three days ago and has no functional impairment could test positive at a roadside check, lose their licence automatically for three months, and — in practical terms — lose their employment. That outcome was the predictable consequence of applying zero-tolerance detection laws to a legally prescribed medication. Dr Will Tregoning from advocacy group Unharmed framed the change plainly: patients were being asked to choose between their medicine and their mobility.

The case for caution: THC does impair driving — the pharmacology is not disputed. Research published in Current Addiction Reports in 2026 confirms acute cannabis use is associated with increased crash risk. The 50 ng/ml threshold for penalties is not a validated impairment cutoff; it is a pragmatic regulatory line. Detection methods still lag behind the science of impairment.

Both of these things are true simultaneously. A law that treated detection as evidence of impairment was producing unjust outcomes for patients on legal prescriptions. A law that removed any consequence for THC-positive drivers — including those who dosed shortly before getting behind the wheel — would be a different problem. The NSW solution sits in the middle: registration, education, a threshold for enforcement, and a one-year review. Whether the threshold is set correctly will only be visible in the review data.

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What this means in general practice this week

GPs who prescribe medicinal cannabis have new information for the prescribing conversation.

In NSW, from late 2026: eligible registered patients on unrestricted licences can drive legally with THC present, under the new framework.

The registration step matters. Patients seeking to drive legally under the new system must register with Transport for NSW and provide prescription evidence. This does not self-activate — patients need to take the steps. GPs can support registration with a standard letter confirming the prescription and the prescribing indication.

The prescribing conversation still needs to include driving risk around acute dosing. The law addresses detection-without-impairment. It does not change the clinical guidance that patients should not drive while acutely impaired. That conversation — timing of doses, the difference between residual detection and acute effect — is still part of informed prescribing.

For patients outside NSW: this law applies to New South Wales only. Victoria, Queensland, and other states retain zero-tolerance detection laws. Patients with prescriptions who drive interstate need to know their protections do not travel with them.

The law is imperfect — the threshold is contested and the exclusion of commercial and P-plate drivers will affect some patients significantly. But it represents the first formal legislative acknowledgement in Australia that detected THC and impaired driving are not the same thing.

Verdict: yes — a meaningful policy change for NSW medicinal cannabis patients that directly affects the prescribing conversation in general practice.

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Sources cited

1. Driving laws changed for NSW medicinal cannabis users — Medical Republic, 18 September 2026