Cannabis may be decriminalised in the ACT, but driving poses a risk

February 2, 2025

Possessing cannabis is decriminalised in the ACT but getting behind the wheel with it in your system is an offence

7h ago7 hours agoSun 2 Feb 2025 at 7:40pm
blurry shot of a man and woman sitting on a park bench
Cannabis user Chris, whose name has been changed, spoke to the ABC about how he won’t get behind the wheel when he smokes.  (ABC News)

In short:

A recent study of cannabis users in the ACT found around 70 per cent won’t drive for at least seven hours afterwards.

Some drivers are getting behind the wheel after consuming cannabis, which researchers described as potentially “risky” behaviour. 

What’s next?

Researchers say more targeted messaging is needed, given the potential negative impacts of impaired drivers on road safety, but better ways of testing are also being explored. 

Now aged in his late 50s, Chris has been a regular cannabis user for most of his adult life. 

These days, he mostly smokes at the weekends.

And when he does, he makes a conscious decision not to get behind the wheel.

Instead, he catches the bus or gets on his pushbike to get where he needs to go over that period. 

But he freely admits he didn’t always exercise that kind of caution. 

Chris, whose name has been changed to protect his identity, says he used to get behind the wheel when he was younger after smoking cannabis. 

“In my youth, I had many an incident,” he said.

“I mean, when you’re young, you tend to, you know, think you’re bulletproof and all that.

“But I’ve had some scary moments, it’s like when I was [driving] and I thought I would [put] the car in reverse because it said “race” so … and that didn’t work very well.”

But he says most of the time when he did drive, he felt he was in control of the vehicle. 

Chris is among those Canberrans who also must run the risk of being stopped by police for a random drug test, which he described as a “bit of a gotcha trap”. 

The tests are able to pick up the presence of a drug, but they aren’t able to measure impairment, meaning even a very small amount shows the same result as a large quantity. 

ACT police agree and say they aren’t testing for impairment. 

Unlike with alcohol, for example, there’s also no threshold in place for drug testing.

police officer
Detective Inspector Mark Steel says police take a zero tolerance approach to drivers being found with drugs in their system. (ABC News: Ian Cutmore)

Detective Inspector Mark Steel, the officer in charge of road policing in Canberra, says that’s beside the point, as police take a zero-tolerance approach to the presence of any drugs in a driver’s system. 

“The message is quite simple, if you’re making that conscious decision to take drugs, well you should be making that conscious decision not to drive,” he said. 

“We’re not health professionals, so we can’t provide advice on how long that drug is going to stay in anyone’s particular system.”

Drivers caught with drugs in their system face an immediate suspension of 90 days and a day in court. 

police drug test roadside
The numbers of roadside drug tests being conducted in the ACT have been declining for several years. (Supplied: ACT Policing)

Despite that zero tolerance approach, numbers of drug tests being conducted in the ACT have been on a downward trend since 2019.

In 2019, more than 4,000 tests were conducted. That dropped to below 3,000 in 2020, around 800 in 2021, back up to 2,700 in 2022 and was just over 1,000 in 2023.

The numbers of drivers being caught have also been declining. 

The number of drivers who were charged with drug driving in 2019 was 850.

By 2023, that had dropped to 200 drivers.

Federal government data from last year showed the ACT had the lowest rates of drug testing in the country. 

A cannabis plant growing indoors in Canberra.
The possession of certain amounts of cannabis has been decriminalised in the ACT since 2020.  (ABC Canberra: Donal Sheil)

Drug decriminalisation hasn’t altered police view

Police say their approach to drug driving hasn’t changed despite the ACT government’s successive introduction of decriminalisation laws, first for cannabis and then for other illicit drugs. 

In 2020, the ACT government introduced legislation which decriminalised the possession and use of cannabis. 

Since then, the possession of up to 50 grams of cannabis per person, and a maximum of four plants per household no longer attracts any penalties. 

Half a decade ago, that was a controversial change in the territory’s drug enforcement regime, and was hotly opposed by the federal government, which threatened to use Australian Federal Police officers to enforce Commonwealth laws against Canberrans.

The ACT government has since decriminalised the possession of small amounts of other illicit drugs including cocaine, MDMA, heroin and meth. 

Study finds most are leaving time before driving

a woman with long blonde hair sits at her desk
Dr Danielle McCartney is a researcher at the Lambert Initiative for Cannabinoid Therapeutics and worked on a recent study of cannabis users in the ACT. (ABC News: Liam Patrick)

Researchers at the Lambert Initiative for Cannabinoid Therapeutics have been interested in the impact of those laws, and how they may be influencing driver behaviour.

The researchers acknowledge there is “significant concern” about the impact of cannabis decriminalisation on road safety.

Cannabis users are advised to wait “an appropriate length of time” before driving. 

a woman with long blonde hair sits at her desk looking at the camera
Dr McCartney says most cannabis users who were surveyed were doing the right thing. (ABC News: Liam Patrick)

But as Dr Danielle McCartney explains, it can be hard to actually know what that time frame should be as cannabis can “persist” for differing amounts of time depending on whether it’s being tested for in blood, oral fluid or urine. 

A recent study of almost 400 cannabis users in the ACT revealed the majority reported waiting more than seven hours after consuming cannabis before driving.

Dr McCartney says while that was a good outcome, it means about 30 per cent are potentially getting behind the wheel while impaired.

And the study showed people who were making the decision to do so were also generally the people who were more likely to endorse other types of risk-taking behaviour like taking larger quantities of cannabis, and generally believing cannabis did not affect their driving.

Perth Police drug testing kit
The numbers of drug tests being conducted in the ACT has been on a downward trend since 2019.  (Jonathan Beal: ABC)

Researchers also acknowledge that broadly speaking “identifying cannabis-affected drivers is a little bit of a tricky thing”. 

“It’s not quite as straightforward as identifying alcohol-affected drivers, and this is because the marker that we typically use … which is concentrations of THC in oral fluid aren’t necessarily all that closely related to the levels of impairment that we see in drivers,” she said.

She says there is a “mismatch” between cannabis being decriminalised and its use being prohibited among drivers and called for a “balanced” approach. 

For example, under a law change expected to come into effect in Victoria in March this year, medicinal cannabis users who test positive to drugs in random roadside tests will no longer lose their licence automatically. 

Instead, magistrates will be allowed to use their discretion when sentencing those with a valid prescription who were not impaired at the time.

“One thing researchers are interested in is developing novel ways of identifying cannabis affected drivers to sort of support that shift in policy,” Dr McCartney said.

In the meantime, she agrees more messaging about the potential negative consequences of driving while impaired is needed.

blurred man speaking to a woman on a park bench
Chris says he encourages young people not to take drugs. (ABC News)

And Chris, who describes his use of cannabis as a “mindset of dependence” had a message of his own:

“I don’t condone what I do,” he said.

“When it comes to others, especially young people, I’m very anti-drugs. I tell them don’t do it.

“It has consequences that you can’t imagine.”

 

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