As of 2016, there were approximately 300,000 Aussies using cannabis daily for medicinal or adult-use purposes. It’s safe to assume that a large majority of those people are drivers. Since 2016 marijuana has become more widely used. And, increasingly people are concerned about whether or not they can drive while using cannabis, particularly CBD oil.

  • If you’re asking whether you can simultaneously drive and consume cannabis – no you can’t.
  • If you’re asking whether you can take cannabis then walk out the door immediately and get into a car and drive – you can’t. 
  • If you’re asking whether you can drive after an extended period of time after taking cannabis or CBD oil – this article is for you.  
driving with any THC is illegal

Regardless of legality, the team at honahlee are the first to tell you not to drive while under the influence of cannabis. Driving while under the influence of cannabis could result in an accident which would not only impact your life but the life of others too.

Article Overview

When deciding whether it’s safe to drive after consuming cannabis, it’s important you understand all of the factors that come into play. While we recommend you don’t drive after taking cannabis, there may be cases where you’ll need to get from A to B and won’t have any other option. By the time you finish this article, you’ll have all the information to make the best decision possible. We’ll cover:

If you’re looking for information on driving laws in each state, you can go to our medical marijuana and driving faq. If you’re worried about being drug tested after taking your medication, you can view the, “How long does cannabis stay in your system,” post.

Feel free to jump ahead to any part of the article or read the entire thing through. If you find this article useful, we’d ask that you share your new-found knowledge with a friend or family member. Let’s get started.

Does marijuana affect your ability to drive?

When driving you want to be as clear-headed as possible. Cannabis is a depressant drug which means that it affects your brain functions and nervous system. That puts cannabis in the same classification of drug as alcohol. We know that cannabis has certain medicinal benefits which alcohol doesn’t, so how much does cannabis actually impact your driving abilities? Let’s look at some of the research.

Does THC affect driving? A motor control & THC study

In 2006 study was created to help develop limits for driving under the influence of cannabis. Some participants smoked cannabis and others were given a placebo. Over a 6 hour period participants were then tested on:

  1. Tracking performance (ie holding a straight line)
  2. Motor impulsivity (ie stopping at a red light)
  3. Executive function (ie general cognitive processes needed to achieve a goal)

Study Results:

thc decreases motor control

In all three tests, the average performance of participants who had consumed THC significantly decreased. They also found that, “THC induced performance impairment were severe and clinically relevant when compared to alcohol effects on the same tasks.” These results suggest that marijuana does affect driving skills.

A Scientific Literature Review:

A 2017 literature review studied scientific research that looked at the relationship between cannabis and injury and death. The review looked at all-cause mortality, occupational injury, motor vehicle accidents, and overdose injuries and death.

cannabis increases risk of crashes

With relation to cannabis and motor vehicle deaths, the team looked at six reviews involving driving under the influence of cannabis. The conclusion of the review was, “there is substantial evidence of a statistical association between cannabis use and increased risk of motor vehicle crashes.”

Is it safe to drive while taking CBD? 

An Australian study from the Lambert Institute published in 2019 looked at cannabidiol (CBD) and THC and impacts on driving and cognition. Participants vaporised cannabis which had a 1:1 ratio of THC to CBD, cannabis that was THC dominant and a placebo. The study found that no matter what the ratio of CBD and THC, cannabis increased the amount of “lane-weaving.”

cannabis increased the amount of lane weaving

The same study also found that increasing CBD does not reduce the symptoms of impairment and in some cases can actually worsen impairment. It’s important to note, however, that this study was done with THC & CBD, not just CBD.

CBD specific information

Recently the World Health Organisation (WHO) published a report on CBD. Regarding CBD and driving there are two noteworthy points:

  • The WHO states, “At present no public health problems (e.g. driving under the influence of drugs cases, comorbidities) have been associated with the use of pure CBD. 
  • A study is cited which gave healthy participants 200mg of CBD orally which did not produce any impairments of motor or psychomotor performance.

However, CBD oil is known to have relaxing effects and to help people sleep. This may then make it seem logical that it could impact your driving. While that is a logical step to take, the only research shows that pure CBD didn’t have an impact on motor performance.

What are the laws about CBD oil and driving in Australia?

The current Australia law states that you are not allowed to drive with any THC in your system. Full spectrum CBD oil contains THC. Broad spectrum or CBD isolate has no THC. At this time, CBD oil is only legal with a prescription. If you have a prescription, many police officers will let you go if you test positive for THC and show no signs of impairment.

The key takeaway here is that pure CBD oil is unlikely to have any impact on your motor skills. However, there isn’t enough research to say definitively. If you’re unsure of whether you should be driving, consult your doctor. 

Driving abilities are impaired by cannabis

Based on the research it would seem that cannabis, particularly THC, does have an impact on your driving abilities. Using cannabis while driving increases the risk of crashing. It’s also important to note that everyone responds differently to cannabis when first consumed and in how long it takes for the effects to wear off. While there isn’t any sort of measure on how much, it’s clear that cannabis affects driving. 

It is clear that more research needs to be done on cannabis and driving before we have any sort of standards for impairment like we do with alcohol.

How long after consuming cannabis is it safe to drive?

presence of thc doesn't mean impaired

We often get asked questions about how long after smoking or ingesting cannabis it’s safe to drive. As mentioned above, the effects of cannabis will be different for everyone. Similarly, how quickly impairment from THC wears off will depend on the individual. 

Because there are no standards around cannabis impairment and there isn’t enough research on the topic, it is very hard to give a scientific answer to the question. Here are a few factors to take into account when deciding when you should drive:

  • The 2006 study presented above tested for impairment up to 6 hours. The study notes, “Performance impairment after THC was usually highest during the first hour after smoking and declined to baseline over 3–4 hours after THC use.“
  • In a presentation from the Australian Cannabis Summit, Paul Mavor says, “The presence of THC in your system doesn’t necessarily mean impairment, however if a patient is impaired, the general rule of thumb is to wait 6 to 8 hours.” 
  • The NSW Centre for Road Safety said that their tests can detect up to 12 hours (approximately) whereas research has shown that cannabis can be detected in your blood and saliva for up to 24 hours post consumption.

So, how much time do you give between cannabis use and driving? Based on this information, in excess of 24 hours after cannabis consumption seems safe. At a minimum, you’re looking at 8 hours before driving. Please remember that impaired driving is not only a threat to your life, but those around you too. Please make sure you don’t drive impaired. Safety for you and others on the road is critical.

Cannabis is only legal in Australia if it has been prescribed by a doctor. Legalities around driving while taking cannabis as a medication differ from location to location. 

To learn specifics about Australia and recommendations from your state body, you can read this short article on driving while taking medical cannabis in Australia. The bottom line in Australia, however, is that driving with any THC in your system is illegal. 

Overseas, Canada has a multifaceted system for testing for cannabis impairment. A 2018 law created standards for cannabis driving impairment which have different fines and penalties based on the amount of THC in your blood. The government has set the levels very low. A member of government said that that they are effectively taking a zero-tolerance approach until the science improves.


Cannabis and driving don’t mix, even more so than alcohol and driving because we don’t have a standards system yet. It’s clear that THC can impact your ability to drive. And, CBD may have physical effects on your system but it’s unlikely to have an impact on your driving. In Australia laws between states vary and some are more strict than others. In Australia, driving with any THC in your system is 100% illegal whether you’re taking medicinal cannabis or otherwise. The bottom line is that you should not drive under the influence of marijuana.

honahlee request driving

Safety for yourself and fellow Aussies is of utmost importance. The cannabis community is for all who need cannabis for health and wellness. Cannabis, however, is a drug and should be used responsibly and only when prescribed. While it may be safe to drive after 8 hours, we ask that if you’ve used cannabis in the past 24 hours please don’t drive.

Everything you need to know about Cannabis, CBD Oil and driving
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Everything you need to know about Cannabis, CBD Oil and driving
You should not drive while impaired by cannabis or any other substance. CBD and THC have different impacts on your ability to drive and it's illegal to drive with any THC in your system Australia-wide.
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