Alcohol and Drugs

Overview

At a Glance: Learner, P1 and P2 drivers must have a blood alcohol concentration (BAC) of zero. Full licence holders must stay under 0.05, and bus, taxi, rideshare, heavy vehicle and dangerous goods drivers must stay under 0.02. Driving with any illegal drug in your system is an offence, even if you feel fine.

Drink and drug driving is one of the major causes of death on NSW roads. The DKT tests three things here: the legal limits, how alcohol and drugs affect you, and what police can do. This guide covers each one in plain English, based on the NSW Road User Handbook.

BAC Limits in NSW

BAC measures how much alcohol is in your blood. Your legal limit depends on your licence and the vehicle you’re driving:

Licence or vehicle	Legal BAC
Learner (L)	Zero
Provisional P1	Zero
Provisional P2	Zero
Full (unrestricted) licence	Under 0.05
Full licence from interstate or overseas	Under 0.05
Learner or provisional licence from interstate or overseas	Zero
Buses, coaches, taxis, rideshare and hire cars	Under 0.02
Heavy vehicles over 13.9 tonnes, dangerous goods vehicles	Under 0.02

A learner’s supervisor must also stay under 0.05. They must not have any illegal drug in their system or be under the influence of any drug.

Key Fact: Zero means zero. For L and P drivers, a single light beer or a small glass of wine can put you over your limit.

How Alcohol Affects Your Driving

Alcohol is a depressant, which means it slows your brain down. It doesn’t sharpen you up. Even one or two drinks can:

• slow your reactions and your decision-making;
• make it harder to judge speed and distance;
• give you false confidence, so you take bigger risks;
• make it harder to do more than one thing at once, so you miss lights, signs and pedestrians;
• make you drowsy.

The more alcohol in your blood, the higher your crash risk, and drink-driving crashes tend to be more serious.

Only Time Lowers Your BAC

Your body clears alcohol at its own pace. Coffee, cold showers, food, water and sleep might make you feel more alert, but none of them lower your BAC. After a big night of drinking, it can take more than 18 hours for your BAC to get back to zero. That’s why the morning after is a real risk.

You also can’t work out your own BAC by counting drinks. Your size, weight, how tired you are and how big each serve is all change the result. The only way to be sure is not to drink at all before you drive.

Plan Before You Drink

The handbook’s advice is simple: if you’re going to drink, sort out how you’ll get home before you start. Options include:

• public transport or a taxi;
• a lift with a driver who hasn’t been drinking;
• staying overnight.

Plan ahead, because alcohol affects your judgement. A decision made after a few drinks is less reliable than one made beforehand.

Breath Testing and Other Tests

• Police can stop any driver at any time for a random breath test (RBT). They can also test any driver involved in a crash.
• You must not refuse a breath test. Refusing carries severe penalties, just like drink driving.
• You must not refuse a blood or urine test after a crash.
• Drinking alcohol while you drive is a separate offence, even if your BAC stays under your limit.

Drugs and Medicines

Illegal Drugs

Mobile Drug Testing uses a saliva sample to check for four drugs:

• cannabis (THC);
• methamphetamine (including speed and ice);
• ecstasy (MDMA);
• cocaine.

Driving with any of these in your system is an offence, whether or not you feel affected. Drugs can stay in your body long after you take them. Police can also test drivers who seem impaired by any drug. If a driver fails a sobriety assessment, blood and urine tests can follow, and these can detect a much wider range of drugs and medicines.

Prescription and Over-the-Counter Medicines

Many common medicines can cause drowsiness, blurred vision, poor concentration and slower reactions. Examples include painkillers, cold and flu tablets and allergy medicine. It’s an offence to drive under the influence of any drug, including a legal medicine.

• Read the label and follow any warning about driving.
• If you’re unsure, ask your doctor or pharmacist before you drive.
• Don’t judge a medicine by how it affected someone else.

DKT Tip: Never mix alcohol with medicines or other drugs. The handbook says the combination is more dangerous than either one alone, and its effects are unpredictable.

Penalties

The handbook lists fines, loss of licence, prison and an alcohol interlock as possible penalties. How serious the penalty is depends on how far over the limit you are and whether it’s a repeat offence. For a first low-range, special-range or novice-range offence, NSW Police can suspend your licence on the spot. For L and P drivers, novice range means any BAC above zero.

If you hold a learner or P1 licence, any loss of licence also sets back your progress towards a full licence.

Practise with the Alcohol and Drugs quiz, or read our guide to NSW alcohol and drug limits for L and P drivers.

Common Mistakes on the DKT

• Picking 0.02 for learners. The 0.02 limit is for professional drivers. L, P1 and P2 drivers must be at zero.
• Thinking 0.08 is a limit. It isn’t anyone’s limit. It’s where mid-range offences start.
• Believing coffee, food or a shower sobers you up. Only time does.
• Assuming prescribed medicine is always fine to drive on. Being under the influence of any drug is an offence.
• Thinking you can refuse a test if you haven’t been drinking. You can’t.
• Thinking your supervisor needs zero BAC. A supervisor must be under 0.05.