Home » Driving under the influence? Get advice today.

The risks of drinking, driving and random breath tests are advertised consistently, from TV to billboards. We are all aware of the two (2) standard drinks in the first hour, and one (1) standard per hour thereafter. These guidelines, equally helpful and dangerous, and other ‘myths’ are explored in our article here.

The risks of taking ‘drugs’ and driving while similarly severe, are seldom made known. We all know it is illegal, but with the increased legalisation of certain drugs, namely cannabis (in some states within Australia or other countries) there has been an increased number of charges being made against persons ‘driving’ while under the influence of a relevant drug or simply having a drug present in their saliva or blood.

What classifies a relevant drug?


Firstly, what is a relevant drug? Under the Drugs Misuse Regulations, this includes but is not limited to:


Methylamphetamine (Ice)
Amphetamine (Speed)

A medical license to possess or use certain drugs is not a viable excuse to operate a vehicle while it is in your system or under its influence.



Driving is not limited to being on the road and behind the wheel. You may be charged with driving under the influence or while a relevant drug is present if you deal with a vehicle (not limited to a car) in the following ways:

Be in charge.
Attempt to put into motion; and/or

This means that you may charged even if you are parked, in the driver’s seat, or the supervisor of learner driver.




An authorised police offer may request an analysis of your saliva if you are driving, or if they have reasonable suspicion you have dealt with a vehicle as above in the preceding three (3) hours.

In most circumstances, it is an offence to refuse to provide your saliva for analysis and may subject you to arrest and subsequent fine of $5,750 or six (6) months imprisonment.
An exception is if you:

1. Have an approved medical certificate stating your illness or disability which prevents you from providing saliva.

Once tested, you have a right to your results.


There are two drug driving offences you may be charged with:

Driving under the influence
Driving while relevant drug is present.

The most common is the second and slightly lesser option because the police only need to show that you tested positive at a roadside saliva test or otherwise, and are not required to prove you are ‘under the influence’ (e.g. your ability to operate your vehicle is measurably affected by the drug).


If you are charged with one of these offences, the sentence for a first offence may be as follows:

  1. Driving while under the influence
    • 6 months disqualification (mandatory minimum)
    • $4,025 fine; or
    • 9 months imprisonment
  2. Driving while relevant drug is present
    • 1 month disqualification (mandatory minimum)
    • $2,012.50 fine; or
    • 3 months imprisonment.

A second and third conviction within five years for drug or drink driving offences means both the mandatory disqualification periods and fine or imprisonment sentences will increase.

Please be aware that testing positive for a relevant drug while driving may provide the police ‘reasonable suspicion’ that you possess that drug and subject you and your vehicle to search and seizure powers, without a warrant being necessary.

For urgent advice or representation please contact our criminal department at Greenhalgh Pickard.