The effects of drugs on driving

Drugs affect each person differently and some people may not even be aware of the affects a drug is having on them, until it’s too late.

Factors such as the quality and quantity of the drug taken, frequency of use, or mixing with other drugs or alcohol, all influence the effect a drug will have at any given time.

The effects of drugs on driving also vary depending on the type of drug.

Drugs can affect your driving by causing:

  • reduced ability to judge distance and speed
  • distorted time, place and space
  • reduced coordination
  • hyperactivity
  • aggressiveness
  • paranoia
  • hallucinations
  • blurred vision
  • convulsions
  • dizziness and fainting
  • fatigue
  • memory loss
  • nausea
  • tremors
  • mood swings
  • unconsciousness
  • muscle weakness.

Random roadside drug testing

Just like random breath tests for alcohol, you can be pulled over by Queensland police officers for a random roadside saliva test to detect any presence of relevant drugs. The tests can be carried out at random breath testing sites and at targeted drug test sites. You can also be pulled over and tested by a police officer if they suspect that you are driving under the influence of drugs.

The facts:

  • Roadside drug tests detect the presence of cocaine, methamphetamine (also known as speed and ice), MDMA (the active ingredient in ecstasy) and THC (the active ingredient in cannabis).
  • In Queensland it’s an offence to drive with THC in your system, even if it’s prescribed by a doctor.
  • There is a zero tolerance in Queensland for drug driving.
  • Police may require a driver to provide a specimen of saliva for analysis.
  • If a police officer suspects your ability to drive has been impaired by any drug, you can also be required to provide a specimen of blood for analysis.
  • Penalties for a first offence can include being disqualified from driving for up to 9 months, fines of over $4000 and up to 9 months prison.

Read further information on roadside drug testing.

More on drug driving

prescripted drugs

Medical fitness to drive

If you have any underlying medical conditions and/or are required to take medications that affect your ability to drive, you may need to notify Department of Transport and Main Roads.

Find out more