Drink driving and drug driving are criminal offences everywhere in Australia — not just traffic tickets. Drink driving is measured by your blood alcohol reading (BAC), and the penalties step up sharply through low, mid and high range. Drug driving is different, and it catches a lot of people out: for illicit drugs, it's enough that the drug is simply present in your saliva or blood — you don't have to be affected by it, and even a trace days later can mean a charge. Almost every conviction comes with a mandatory licence disqualification, and the serious end carries fines, interlocks, and even jail.
The whole idea in one picture
Tested, ranked, and off the road
A roadside test gives a reading. For alcohol, the range you fall into sets the penalty; for drugs, the mere presence is enough. Either way, a disqualification usually follows.
The drink-driving ladder
Drink driving is built around your blood alcohol reading. The higher the range, the steeper the penalty:
The limits
0.05 — full licence holders
0.00 — learner and P-platers, truck and bus drivers, and many commercial drivers
The three ranges
Low — 0.05 to 0.079
Mid — 0.08 to 0.149
High — 0.150 and above
Two ways to be charged: by the number (a PCA charge, based purely on your reading) or by impairment (DUI, based on how you were driving — which can apply regardless of the reading). And refusing the breath test is itself an offence, often treated as seriously as a high reading.
Drug driving works differently
Police use roadside saliva swabs to detect cannabis (THC), methamphetamine, MDMA, and cocaine. The catch is in how the law treats a positive result:
Presence alone is enough. For illicit drugs, the offence is strict liability — if the drug is in your system, you can be charged even with a tiny trace, even when you feel completely fine, and even days after use. You don't have to be impaired, and "I wasn't affected" is not a defence to a presence charge. Refusing or failing the test is also an offence.
What happens at court
Drink and drug driving usually moves fast — your licence can be affected before you ever reach court:
Charge & suspension — police may issue an immediate notice of suspension.
Court attendance notice — you're given a date to attend court.
Plea — guilty proceeds to sentencing; not guilty sets a hearing.
Sentencing — the court weighs your reading, your record, your need for a licence, and any traffic offender program.
Interlock — many drivers must fit an alcohol interlock device for a set period afterwards.
Choose your state
How it works where you are
New South Wales
NSW
What a conviction means
Automatic disqualification, with set minimums
Under the Road Transport Act, every drink or drug driving offence carries an automatic disqualification with a minimum period.
Disqualification is usually mandatory. Unlike many offences, losing your licence isn't up to the court's discretion — a conviction triggers it. The length, the fine, and whether jail is on the table climb with your range and any prior offences.
Disqualification
Also expect
Common defences
Many cases rest on the test result — so defences often challenge how that result was obtained:
Unlawful stop or search
Police didn't have a proper basis to test you.
Faulty or expired equipment
The testing device wasn't working or in date.
Wrong procedure
No valid reading was taken within the required timeframe.
Medical factors
A condition affected the reliability of the result.
The reading, the procedure, and your need for a licence can all shape the outcome — and a lawyer can sometimes reduce the disqualification. We can point you to traffic lawyers in your state.
This page explains how these charges generally work — it can't tell you what will happen in your case. Limits, ranges, disqualification periods and interlock rules vary by state. If you've been charged, talk to a traffic lawyer before your court date — early advice can affect the outcome.
Criminal lawyers
Hiring a Criminal Lawyer is Essential if You’ve Been Charged
While we don’t provide legal advice—as every case is unique and only a qualified lawyer is permitted to do so—we’ll do our best to guide you with relevant general information. If we’re unable to assist, we can refer your query to a criminal lawyer.
