What a Positive Roadside Drug Test Means
What happens if you test positive at the roadside?
A further sample is taken and sent for laboratory confirmation. A positive roadside screen is not the end of the process, because the result must be confirmed by a laboratory before the penalty is finalised. Understanding how charges are dealt with helps you see how a first offence is usually resolved without court.
Importantly, this is a presence offence. It is based on a drug being detected in your system, not on proof that your driving was affected, which is a separate and more serious matter. That distinction shapes both the penalty and any challenge.
What drugs does the roadside test detect?
The roadside oral fluid test screens for common illicit drugs. It targets THC, the active component in cannabis, methamphetamine, and MDMA, which are the drugs the test is designed to detect. A positive screen for any of these leads to the confirmation process.
Because it is a presence test, it can detect a drug some time after use, not only while you are affected. This is why people are sometimes surprised by a positive result, and it is one reason the exact circumstances are worth reviewing.
The Penalties and Your Licence
What are the penalties for a first drug driving offence?
A fine and a licence loss, usually without court. For a first offence, the penalty is generally a fine of 3 penalty units and a 6-month licence suspension, dealt with by an infringement notice. You must also complete a drug driver behaviour change program, and Transport Victoria’s drug driving penalties guidance sets out these requirements.
The program is not optional. If you do not complete it within the required time, your licence can be cancelled, so it needs to be treated as a firm requirement rather than a formality.
What happens for a second or later offence?
It is more serious and goes to court. A second or later drug driving offence is heard in the Magistrates’ Court, carries higher fines, and brings a longer licence loss, generally a cancellation of at least 12 months. The table below sets out the difference.
| Offence | Typical outcome |
| First offence | 3 penalty units, 6-month loss, infringement, program |
| Second offence | Higher fine, at least 12-month loss, court |
| Third or later offence | Higher fine again, longer loss, court |
A later offence also brings a more intensive program and a zero BAC condition on relicensing. This is where the consequences escalate sharply, much as they do for repeat driving offences generally, so a second matter should always be taken seriously.
Can You Challenge It, and What Should You Do?
Can a positive roadside test be challenged?
Sometimes, depending on the circumstances. A positive screen must be confirmed by a laboratory, and the process, the sample, and the timing can occasionally be open to challenge. It is more limited than for many charges, but it is not automatically beyond question, unlike the clearer thresholds in matters such as dangerous driving charges.
Whether a challenge is realistic depends on the facts. Because it is a presence offence, arguing you were not affected does not assist, so any challenge focuses on the testing process rather than your level of impairment. Advice is worthwhile where you genuinely dispute the result.
What should you do next?
Deal with the requirements and get advice if it is a later offence or you dispute the result. For a first offence, complete the program and plan around the licence loss, and note the effect a later matter can have. For a second or later offence, or a genuine dispute, our work on driving and traffic charges can help.
Keeping a clean record from here matters, because a later offence escalates quickly and affects the effect on your record.
It is a different kind of matter from a licensing offence like a mobile phone fine, but the same principle applies: act on the requirements promptly.
