If you undergo a roadside drug screening test and test positive for THC (cannabis), methamphetamine, MDMA, or cocaine, and subsequently test positive in the laboratory for one or more listed qualifying drugs, you will receive an infringement notice.

Alternatively, if you are pulled over for driving suspiciously and/or if drug impairment is suspected, you will likely be asked to complete a compulsory impairment test (a behavioural test at the side of the road). If you fail this, a blood sample may be required.

The outcome of the blood test would determine any enforcement action if you have driven after consuming a qualifying drug or drugs, and/or alcohol over the legal limits.

If it is a medicine, you have a valid and current prescription for, and you have taken the medicine as prescribed you may apply for a medical defence.