Alcohol limits, drugs and medicines
Know the alcohol limit that applies to you when driving in NSW. Understand the rules if you're on medication. Don't drug drive.
Alcohol and driving – the rules
Alcohol affects your driving. It puts your safety and the safety of your passengers and other road users at risk.
Drink driving is one of the major causes of death on NSW roads.
Blood alcohol concentration (BAC)
Your blood alcohol concentration (BAC) must be under the legal limit when driving.
The legal limit depends on your driver licence or vehicle type:
|Driver licence or vehicle type||Blood Alcohol Concentration (BAC)|
Full (unrestricted) licence (C) or (R)
Fully licensed driver from interstate or overseas
Public passenger vehicles (for example, buses, coaches, taxis, rideshare vehicles and chauffeur‑driven hire cars)
Heavy vehicles with a gross vehicle mass (GVM) over 13.9 tonnes
Vehicle and trailer combinations with a gross combined mass (GCM) over 13.9 tonnes
Dangerous goods vehicles
It’s impossible for you to estimate your own BAC, even if you think you know how many drinks you’ve had. Your size and weight, how tired you are and variation in alcohol servings can all affect your BAC.
The only way to be sure you’re under the limit is to not drink alcohol at all.
Driving under the influence of alcohol
You must not drive under the influence of alcohol.
If you think you might be under the influence, do not drive.
Drinking alcohol while driving
You must not drink alcohol while in your vehicle and driving, even if your BAC stays below your legal limit.
Random breath tests (RBT)
You must not refuse an RBT by the police.
Police can stop you anytime and test your BAC by asking you to speak or blow into a breath-testing device. Police can also breath‑test any driver involved in a crash.
Blood and urine tests
You must not refuse a blood or urine test if asked to take one after a crash.
If you’re involved in a crash that’s fatal (or likely to be fatal), police can arrest you to take blood and urine tests.
If you’re admitted to hospital after a crash, medical practitioners can take blood and urine tests for the police.
Drink driving penalties
There are severe penalties for driving over the legal alcohol limit or under the influence of alcohol, or refusing a blood or breath test.
Penalties can be fines, loss of licence, prison or an alcohol interlock on your vehicle. The penalty depends on how much you’re over the limit and whether it’s a first or repeat offence.
If you drink alcohol while driving, you can get a fine and demerit points.
See the Penalties for drink driving.
Medicines and over-the-counter drugs
Medicines can affect your ability to drive safely. They can cause drowsiness, blurred vision, poor concentration, slower reaction times and changes in behaviour.
Some medicines that can affect driving are:
- pain killers
- medicines for blood pressure, nausea, allergies, inflammations and fungal infections
- tranquillisers, sedatives and sleeping pills
- diet pills
- cold and flu medicines.
Read the label and get medical advice
Read the labels on your medication to determine whether it could affect your driving. If there’s a warning label that tells you not to drive, follow that advice.
Some labels say a medicine may affect your ability to drive. If you’re not sure, get advice from your doctor or pharmacist, and do not drive until you’ve done so.
Don't mix drugs and alcohol
While you should never drink drive or drug drive, it’s even more dangerous to take drugs while drinking alcohol, or to combine drugs. This includes prescription and over-the-counter medicines. The effects are unpredictable. Never drive if you’ve mixed drugs, or if you’ve taken drugs while drinking alcohol.
Drugs and medicines – the rules
Any drugs including illegal drugs, prescription and over-the-counter medicines can affect your driving and put the safety of passengers or other road users at risk. They can also change your behaviour, causing you to take risks you usually would not consider.
If you think you might have illegal drugs in your system or be under the influence of any other drug or medicine, do not drive.
Presence of illegal drugs
You must not drive with the presence of illegal drugs in your system.
Drugs can remain in your system for a long time after you’ve taken them. Police can test any driver or supervisor in NSW for four common illegal drugs through Mobile Drug Testing (MDT):
- methamphetamine (including speed and ice).
If you think you might have illegal drugs in your system, do not drive.
Illegal drugs increase your crash risk
Safe driving needs clear judgement and concentration. You have to react quickly to changing situations on the road. Illegal drugs cause changes in the brain that can impair your driving ability and increase your risk of having a crash.
Stimulants such as ecstasy, cocaine or methamphetamine can make you think you’re driving better than you actually are. They can also make you drive aggressively and take more risks.
Heroin and other opiates such as morphine, codeine and methadone can make you drowsy and reduce your reaction time.
Cannabis can also reduce your reaction time, alter your perception of distance and time and your ability to make the right decisions.
Other illegal drugs also affect your driving. Do not drive if you’ve taken any illegal drugs. See Effects of illegal drugs – Centre for Road Safety
Driving under the influence of drugs or medicine
You must not drive while under the influence of any drug, including illegal drugs, prescription medicines and over-the-counter medicines.
If you think you might be under the influence of a drug or medicine, do not drive.
You must not refuse drug testing by the police.
There are 2 ways to test for drug driving.
Saliva (oral fluid) test
Police can randomly stop and test the saliva of any driver for the presence of illegal drugs. You’ll need to wipe a test stick down your tongue to check if you have illegal drugs in your system.
Blood and urine test
Police can also stop and test drivers who show signs of being under the influence of a drug, including prescription drugs. Police will do a sobriety assessment – a test to determine if you’re affected by drugs. If you fail, you can be arrested and taken to hospital to give samples of blood and urine for drug testing.
If you’re involved in a crash that’s fatal (or likely to be fatal), police can arrest you to take blood and urine tests. If you’re admitted to hospital after a crash, medical practitioners can also take blood and urine tests.
Blood and urine tests cover a large range of drugs and medicines that can impair drivers.
Drug driving penalties
Drug driving is a serious offence. If you drive with illegal drugs present in your system, you can get a fine and lose your licence.
Penalties are even heavier if you drive while under the influence of a drug, including illegal and prescription drugs. You can get a fine, lose your licence and even go to prison.