Drugs & driving

Get the facts

Safe driving requires good judgement and sharp concentration. You need to react quickly to changing situations on the road. Using illicit drugs causes changes in the brain that can impair your driving ability and increase your crash risk.

The effects of drug use depend on the type and concentration of the drug taken and vary widely between individuals. When it comes to illicit drugs, it's hard for users to know the exact chemical substance, the dosage and how long the effects will last.

Prescription drugs and over-the-counter medicines can also reduce your ability to drive safely. Drugs can affect your eyesight, concentration, mood and coordination and cause slower reaction times.

Mixing one drug with another, or mixing alcohol with other drugs, increases your risk of having a crash.

Illegal drugs


Marijuana, weed or hash

Cannabis slows down your reaction time and reduces your ability to respond to situations. It also changes your perception of distance and time, lowers your concentration, reduces coordination and makes you drowsy. Cannabis users often don’t realise their driving is affected until they're faced with an unexpected situation. It's only after they're in danger that they realise they're incapable of making a quick or correct decision.


Speed, ecstasy or cocaine

If you take stimulants such as ecstasy, cocaine, speed, crystal meth, or base you're likely to:

  • believe you drive better than you can
  • drive aggressively and take more risks
  • be overstimulated and lose concentration
  • have blurry or limited vision
  • see things on the road that aren’t where you think they are.

Driving when you’re ‘coming down’ is also dangerous. The effects of stimulants wearing off can also impact your coordination and ability to concentrate. You may also fall asleep at the wheel.


Heroin, methadone or codeine

Using heroin and other opiates such as morphine, codeine, and methadone:

  • makes you sleepy
  • slows your reaction time
  • makes you lose balance, coordination and concentration
  • reduces your ability to pay attention to what’s happening on the road.

Combining alcohol and opiates multiplies the depressant effects of both drugs, even if you only use small quantities. You'll feel drowsy, uncoordinated and be more at risk of falling asleep at the wheel.

Prescription drugs

Many prescription and non-prescription medicines affect your ability to drive or ride safely.

Combining different medications may have an even greater effect on your ability to drive safely. Negative effects of prescription and over-the-counter medications include drowsiness, blurred vision, poor concentration, slower reaction times and aggressive behaviour.

Tools and tips 

Tips for drivers who take medication

  • Ask your doctor or pharmacist whether it is safe to drive.
  • Always read and follow the instructions on the medicine’s warning label.
  • Remember that the medicine might affect your driving more when you first start taking it. Over time, you may get used to it and experience fewer side effects.
  • Don't stop taking your medicine or change the dose without talking to your doctor first.
  • Talk to your doctor about switching any medicine that affects your driving.
  • Don't take more than the prescribed dose of the medicine.
  • Don't drink alcohol or take other drugs while you’re taking medicine.
  • Don't drive if you've missed a dose of medicine that you need to control symptoms that could affect your driving.
  • Arrange another form of transport, such as public transport or a taxi.
  • If you have concerns about how a drug may affect your ability to drive safely, it’s best to discuss this with your doctor or pharmacist.

Find out more about the types of medicines that can affect your ability to drive safely on the health direct website.

Some cannabis medicines prescribed by a doctor contain THC. It's illegal to drive with THC in your system, including when it is used as a medicine, and it could be detected by police through a mobile drug test.

If you're taking a cannabis medicine, speak to your doctor about whether it contains THC and what it means for your driving. More information about cannabis medicine is also available from the NSW Government's Centre for Medicinal Cannabis Research and Innovation.

Mobile drug testing

The NSW Government has a zero tolerance for drug driving.  This stops drivers from putting themselves and others at risk by getting behind the wheel after using drugs.

In June 2021, a new law introduced harsher penalties for combined drink and drug driving offences.

Penalties for a combined offence are tougher than those for separate offences of drink or illicit drug driving.

These penalties send a clear message that mixing alcohol and illicit drugs and then getting behind the wheel will not be tolerated on our roads.

Mobile Drug Testing (MDT) detects the presence of 4 common illegal drugs: ecstasy, cannabis, cocaine, and methamphetamine (including speed and ice).

MDT can be conducted at roadside operations along with random breath testing (RBT), or by NSW Police in vehicles patrolling our roads.

Illegal drugs can still be detected in your saliva by an MDT for a significant length of time after drug use, even if you feel you're OK to drive. The detection period varies depending on the type of drug, amount taken, frequency of drug use, and other factors that vary between individuals.

If you think you may have illegal drugs in your system, the best decision is not to drive.

How MDT works

As with RBT, you'll be stopped by police, asked for your licence, and complete a breath test for alcohol. Following this, the procedure for MDT is:

  • You'll be asked to wipe an MDT test stick down your tongue to check if you have illegal drugs in your system.
  • The results take a few minutes and you must wait until police say you're in the clear. Most drivers test negative and are soon on the road again.
  • If your MDT test is positive, you’ll be taken to a roadside testing van/bus, or back to a police station to provide a saliva sample.
  • This sample will also be tested and if positive, you’ll be banned from driving for 24 hours. All samples are sent to a laboratory for analysis.

Driving under the influence of an illegal, prescription or over the counter drug

You can also be charged with Driving under the influence (DUI) of illegal or prescription drugs, if you are driving while affected by a drug. Drugs are detected through blood and urine tests which are ordered if a police officer has reasonable suspicion that a driver is under the influence of a drug or drugs.

You'll be taken to a hospital to give blood and urine samples for drug testing. This testing can detect a wide range of illegal drugs and medicines.

The penalties for a DUI offence are higher than for a presence offence (detected by MDT). All drivers involved in fatal crashes in NSW undergo blood and urine testing for drugs and alcohol.

Plan ahead to get home safely

If you’re affected by alcohol or other drugs after a night out, trying to drive or ride home puts you and other road users in danger.

For your own safety and the wellbeing of others, have a Plan B to get home.

If you are planning a big night out, plan ahead

  • Leave the car at home when you go out.
  • Use public transport:  Trip Planner.
  • Take a taxi or book a ride share.
  • Get a lift with someone who has not been drinking or using drugs.
  • Stay at a friend’s house.
  • Tell a friend or let someone know if you’ve been drinking or have taken drugs and don’t feel well enough to drive.
  • Walk home, but take extra care.