Driving is complicated enough as it is. You’re dealing with traffic, road rules, other drivers who might not be quite sure of the road rules, weather conditions and countless other distractions. Your ability to react to situations needs to be in top working order.

People often convince themselves that they’re okay to drive under the influence of drugs or alcohol, but more often than not, they’re kidding themselves. Driving under the influence of drugs and/or alcohol is a sketchy business. 

Next to suicide, road accidents are the leading cause of death of young people in Australia

If you’re a learner or probationary driver, it’s illegal to drive with any alcohol in your system at all, meaning you must have a blood alcohol concentration (BAC) of zero. This also goes for truck, bus or taxi drivers and people who have committed drink driving offences in the past.

For everyone else, the law states that you must have a BAC of less than 0.05. However the number of drinks needed to be over the limit varies from person to person. Depending on your size, body fat and gender (i.e. a woman will almost always have a higher BAC reading than a man who drinks the same amount).

Next to suicide, road accidents are the leading cause of death of young people in Australia. In Victoria alone, about a quarter of drivers who are killed in car accidents every year have a blood alcohol concentration (BAC) of .05 or more. Driving under the influence of alcohol can slow down your reaction time, make it difficult to see what’s in front of you and reduce your ability to concentrate. Mixing alcohol with other drugs or medicines can increase these effects further.


If you’re caught driving with a BAC over .05 you could lose your license and face heavy fines, even possible imprisonment for the more serious offences.

The safest way to drink and drive is to not do it at all.

If you do happen to find yourself in a situation where it’s unsafe to drive home, many young people have found it helpful to have a pre-arranged ‘no questions asked’ safety plan in place with mum, dad, or another trusted adult.  It’s better to be in a bit of trouble with mum or dad, than to end up in hospital or worse. If you can’t get a ride, designate a non-drinking driver, take a cab, use public transport or let someone know where you are and stay the night if it’s safe to do so. It’s definitely not worth the risk.


When it comes to driving under the influence of illicit drugs like cannabis and amphetamines, the law is pretty black and white. If you’re found to have any traces of illegal substances in your system while behind the wheel of a car, you will almost definitely face a heavy fine, loss of license and/or imprisonment in the more serious cases.

These types of drugs can stay in your system for days or even weeks, depending on how much you’ve taken and how often. You could get a positive result on a roadside saliva swab test, even if you’re not intoxicated at the time and haven’t smoked for days.

Driving under the influence of drugs can affect people in different ways. It might slow down your reaction times, impair your perception, reduce your ability to concentrate and/or give you a false feeling of confidence, causing you to make irrational, dangerous decisions. Mixing alcohol with drugs or medicines can increase these effects further.


It’s illegal to drive while affected by any drug, whether that drug is legal or illegal (although defences may apply for some prescription drugs). Check any prescribed medications for warnings regarding operating a vehicle or any other machinery while you’re taking it.

To be on the safe side, save the driving for when you’re sober and have the reflexes of a cat.