Alcohol and driving laws
Alcohol is a major factor in road deaths and serious injuries in Victoria.
Blood or breath alcohol concentration (BAC) is a measure of how much alcohol is in your body.
At a BAC of .05, your risk of being involved in a road crash is about double compared with a BAC of zero. Each year, about 1 in 5 drivers killed in road crashes has a blood alcohol concentration (BAC) of .05 or above.
Most fully licenced drivers must have a blood alcohol concentration (BAC) below 0.05. This includes people supervising learner drivers.
Police can check your BAC during roadside drug and alcohol testing.
These laws apply on private property and public roads.
View more information on drink driving offences or combined drink and drug driving offences.
Alcohol testing
Victoria Police undertake random roadside breath testing.
It is a serious offence to not:
- stop at a booze bus or random breath testing station
- provide a breath or blood sample
- cooperate with police who are trying to carry out a breath or blood test.
The penalty for refusing to take a breath test is generally more serious than the penalty for exceeding your BAC limit.
Some drivers must have a BAC of zero (0.00)
You must have a BAC of 0.00 if you:
- have a learner permit
- have a probationary licence (P1 or P2)
- have a driver’s licence or learner’s permit with a ‘Z’ or ‘I’ condition
- are a restricted motorcycle rider (an ‘E’ condition on your licence)
- are a driving instructor
- drive a bus or commercial passenger vehicle (for example, a taxi)
- drive any rigid or articulated truck greater than 4.5 tonnes gross vehicle mass (GVM).
If you meet any of these criteria, it is an offence to drive with a BAC that is over 0.00.
Drinking alcohol in a vehicle
You must not drink alcohol while:
- driving a motor vehicle
- sitting beside a person who is learning to drive.
It is illegal to drink alcohol as a driver or supervisor even if your blood alcohol concentration stays below your legal limit.
You can be fined and receive an infringement notice of up to ten penalty units. If you receive an infringement notice, the penalty is two penalty units.
Passengers can drink alcohol in a vehicle but should avoid it as it can distract the driver.
Drink-driving and road safety
How drinking affects driving
Driving is a complex task requiring concentration, judgement and decision making. Alcohol affects these skills and decreases a driver’s ability to safely control their vehicle.
At a BAC of .05, your risk of being involved in a road crash is about double compared with a BAC of zero.
Drink driving statistics from TAC indicate that the vast majority (99.7 per cent) of drivers tested do not exceed their legal blood alcohol levels. However, in the last five years, around one in five drivers and riders who lost their lives had a BAC greater than .05.
How alcohol affects the brain
Alcohol is a depressant that:
- slows your brain so that you can’t respond to situations, make decisions or react quickly
- reduces your ability to judge how fast you are moving or your distance from other cars, people or objects
- gives you a false sense of confidence - you may take more risks, thinking that your driving is better than it really is
- makes it harder to multi-task – while you concentrate on steering, you may miss seeing traffic lights, passengers or cars entering from side streets
- affects your sense of balance – a huge risk if you ride a motorcycle
- makes you drowsy – you could fall asleep at the wheel.
If you have been drinking, allow plenty of time for the alcohol in your bloodstream to reduce before driving. Cold showers, exercise, black coffee, fresh air or vomiting do not help.
Please note that if you have drunk a lot of alcohol the night before, you are still likely to be over the legal limit the next day, or hungover. You should rethink driving or using heavy machinery the next day, especially if you are a learner or probationary driver, or a professional driver on zero BAC.
A hangover will make you feel unwell and tired, and is another reason why you shouldn't drive the next day. If you know that you need to drive the next day, make the decision to not drink the night before.
Alcohol affects people differently
Two people can drink the same amount of alcohol but register different BACs.
This is because:
- a smaller person will have a higher BAC than a larger person
- a person with a lot of body fat tends to have a higher BAC
- a woman will almost always have a higher BAC than a man of a similar size who drinks the same amount.
As there’s no easy way to know that you are okay to drive after drinking, the only way to be sure is to not drink alcohol if you are going to drive.
Coin operated and commercially available breath testing units that measure BAC can be used as a guide. They should not be relied on because they can be inaccurate. They also can’t be used as evidence in case of a drink driving charge. It’s best to completely separate your drinking from driving.
Don't drink alcohol with drugs, medicine or stimulants
Don’t drink alcohol when you’re taking other drugs. Small amounts of alcohol, combined with drugs or medications, can reduce your ability to drive safely.
This applies to:
- medicines prescribed by your doctor, or bought in a supermarket or pharmacy
- illicit drugs such as cannabis and speed.
Mixing alcohol with energy drinks is dangerous. Energy drinks can mask the effects of alcohol. The caffeine makes you feel more alert, and you may be drunk without realising it.
Never drive if you’ve had alcohol mixed with drugs, medicines or stimulants.
Plan ahead
Always plan ahead and use other ways to get home safely.
If you are going to drink, the safest option is that you don’t drive. If you are going to drive, don’t drink.
You can avoid drink driving by:
- having a designated driver who will not drink or take drugs
- hiring a taxi or ride share
- using public transport
- staying the night (make sure you are not over the limit in the morning)
- arranging for someone to pick you up
- only accepting a lift if you are certain the driver has not been drinking or using other drugs
- always having a plan B if plan A goes amiss.
Useful legislation
Laws about driving with alcohol and drugs are published in the Road Safety Act 1986, Part 5 - Offences involving alcohol or other drugs.