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Cannabis and driving

Written by Let's Budvocate. Laws last checked 25 October 2026.

Disclaimer

The information provided is for educational and informational purposes only. It is not legal advice. Laws change, so check the official source for your state, and get legal advice if you’ve been charged. Read our full disclaimer.

This page isn’t here to tell you off. Plenty of people who consume cannabis also drive, but the laws don’t always work the way people expect, particularly when it comes to the difference between THC being present and someone actually being impaired.

The short version

In most of Australia, it’s an offence to drive with THC in your system. It doesn’t matter if you feel fine.

A prescription usually doesn’t change that. There are a few exceptions in some states, covered below.

There’s no reliable waiting time that guarantees a negative roadside test. THC can remain detectable after its impairing effects have worn off.

It’s about THC being there, not being high

Roadside drug tests check whether THC is in your saliva. They don’t measure whether you’re affected. In most states and territories, a confirmed result is enough for an offence, even if you consumed the day before and feel completely normal.

Driving while impaired by cannabis is a separate offence and can carry more serious penalties.

How long should I wait?

There isn’t a reliable number. How long THC stays detectable depends on how much you had, how you consumed it, how often you consume and your own body. Official advice in Victoria is that a definitive timeframe can’t be given.

If you know you’ll be driving, don’t rely on a fixed waiting time after consuming THC. How long it remains detectable varies, and feeling normal doesn’t guarantee a negative test. Planning ahead, like arranging a lift, using public transport or staying over, is the simplest way to avoid that uncertainty.

How cannabis affects driving

THC can slow your reactions, make it harder to concentrate and affect how steadily you keep to your lane. Mixing cannabis with alcohol can increase these effects further, making it harder to judge how impaired you actually are. Our page on cannabis and alcohol covers that combination.

If you have a prescription

In most of Australia, a medicinal cannabis prescription isn’t a defence. It’s treated the same as any other THC. The exceptions:

Victoria: a prescription isn’t a defence, and you can still be found guilty and fined. But since 1 March 2025, a magistrate can decide not to cancel your licence. Things they look at include whether it’s your first offence, whether you were impaired, and whether you were taking a legal medicinal cannabis product as prescribed, with a prescription that was valid at the time.
Tasmania: it isn’t a THC presence offence if your cannabis was lawfully prescribed and dispensed and you took it as directed. Since 16 February 2026, that includes prescriptions from other states and territories. Driving while impaired is still an offence.
NSW: a new registration scheme for eligible medicinal cannabis patients has been passed but hasn’t started yet. Until it does, the normal rules apply. If it’s relevant to you, keep an eye on Transport for NSW for the start date.

Laws and proposed reforms differ across Australia. Some jurisdictions are considering changes, while others have retained their existing approach. If you’re a medicinal cannabis patient, talk to your prescriber about driving and check the official information for the state or territory where you’ll be driving.

Which law applies?

The law where you’re driving, not where you live or where your prescription is from.

Official information for your state

Laws change, especially for medicinal cannabis. These are the places to check:

Victoria: Transport Victoria
New South Wales: Transport for NSW
Queensland: Drugs and driving (Queensland Government) (penalties double from 1 December 2026, see the government announcement)
South Australia: Law Handbook (Legal Services Commission of SA)
Western Australia: Road Safety Commission (and Legal Aid WA for legal help)
Tasmania: Road Safety (Alcohol and Drugs) Act 1970, section 6A
ACT: Road Transport (Alcohol and Drugs) Act 1977 (changes are being considered, see the Legislative Assembly inquiry)
Northern Territory: Drug driving penalties (NT Government)

If you’ve been charged

Get advice before you go to court. Legal Aid in your state or territory, or a community legal centre, can help, often for free. If you have a prescription, bring the details.