Drugs and driving

Police can test you for drugs at any time. You can lose your licence if you’re found to have drugs in your system while in charge of a vehicle, even certain prescription medications.

When you need legal advice

Get legal advice if you:

  • have been charged with a drug driving offence
  • want to appeal a Magistrates Court decision
  • want to apply for a work licence.

How to get legal advice

Driving or in charge of a vehicle with a relevant drug in the saliva or blood

Police can pull you over for a random drug test at any time. They will take a saliva sample from you for this.

Saliva drug tests used by police can detect:

  • delta-9-tetrahydrocannabinol (THC), which is the psychoactive ingredient in cannabis
  • 3, 4-methylenedioxy-N-methamphetamine (MDMA), which is commonly known as ecstasy
  • cocaine
  • methylamphetamine, which is commonly known as ice.

By law, these drugs are referred to as ‘a relevant drug’.

Police use a two-step process to detect the presence of a relevant drug. They will first ask you to deposit saliva on a small testing strip that they will test in their portable instrument.

If that test is positive, then they will ask you to supply a larger specimen of saliva on a swab. Police then send part of this specimen for further testing in a forensic laboratory. The lab test is much more precise, and can tell the difference, for example, between dexamphetamine and methamphetamine.

You are breaking the law if you drive, or are in charge of a vehicle, with a relevant drug in your saliva or blood.

Police do not have to prove a relevant drug has caused you to drive unsafely. They only need to show you had a relevant drug in your saliva or blood at the time of testing.

You can’t drive with a relevant drug in your saliva, even if the drug has been medically prescribed.

You can only be charged with having a drug in your saliva if it is one of the 4 relevant drugs. However, if you are impaired or intoxicated while driving or in charge of a vehicle because of any drug, then you can be charged with driving under the influence.

Driving under the influence of drugs is more serious than being charged with having a relevant drug in your body.

Prescription and over-the-counter drugs

Taking more than the prescribed or recommended dose of an over-the-counter medication increases your risk of drug driving.

Even if you don’t take more of a medication than you are supposed to, you could still be under the influence of a drug or have a relevant drug in your saliva or blood, if you take the medication and drive. You can still be under the influence of a drug, even if you do not exceed the prescribed or recommended dose.

Always check the medication information leaflet for:

  • warnings about possible side effects
  • impacts on safe driving
  • relevant drugs in the ingredients.

Speak to your doctor or pharmacist if you are unsure whether you can drive safely while taking a medication.

Refusing a saliva or blood test

You can be charged with failing to supply a saliva specimen if you refuse to undergo a random drug test.

It is illegal to refuse a saliva or blood test when:

  • police reasonably suspect you were driving or in charge of a vehicle within the previous 3 hours
  • you were driving at the time of a road accident. 

You do not have the right to ask for a blood test instead of a saliva test, or a saliva test instead of a blood test.

Going to court for a drug driving offence

If the court finds you guilty of drug driving or refusing to undergo a drug test, you may receive a:

  • fine
  • community service order
  • probation
  • jail sentence.

You will also be disqualified from driving.

This means:

  • your licence will be cancelled immediately
  • you must hand in your driver licence to the court or Department of Transport and Main Roads.

It is an offence to keep a cancelled driver licence.

If you want to apply for a work licence, get legal advice before going to court.

We may give legal advice about drug driving offences if: 

  • you plan to plead not guilty to a drug driving charge
  • you want to know the likely penalty and what you can do to try and get the minimum possible penalty
  • you want to apply for a work licence.

Other places to get legal advice:

Disclaimer: This content is for general purposes only and not legal advice. If you have a legal problem, please contact us or speak to a lawyer. View our full disclaimer.

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