There is no fixed schedule for when Victoria Police conduct roadside drug testing. Officers can stop any driver at any time to test for traces of THC (the active ingredient in cannabis), methamphetamine, and MDMA (ecstasy).
These tests can be carried out by any Victoria Police officer — whether they are in uniform, on a motorcycle, in a patrol vehicle, or in plain clothes.
Drivers are asked to provide a saliva sample by placing a small absorbent pad on their tongue for a few seconds.
If you’ve been charged after a roadside drug test or are facing licence suspension for a drug-driving offence, it’s crucial to get professional legal advice before making any decisions. The laws surrounding drug testing and driving in Victoria are strict, and penalties can be severe — but you still have rights.
Contact drug offences lawyers in Melbourne for confidential guidance. Experienced traffic lawyers can assess your situation, explain your options, and help you achieve the best possible outcome in court or with Victoria Police.
How Roadside Drug Testing Works
When stopped, drivers must provide a saliva sample by placing a small absorbent pad on their tongue for a few seconds.
The sample is then analysed at the roadside, a process that takes about three minutes.
If the initial test is positive, a second test is conducted. Should that also test positive, the sample is sent to a laboratory for confirmation.
Only the results of this laboratory analysis determine whether a driver will be charged.
Any driver — at any time — can be asked to take a roadside drug test. It’s worth noting that prescription and over-the-counter medications (like cold or flu tablets) are not detected by these saliva tests.
How Long After Taking Drugs Can You Be Detected?
There is no precise timeframe for how long drugs stay in your system. Detection depends on several factors, including the type of drug, amount taken, and your metabolism.
Drug traces can be found in saliva for several hours after use.
Even if you no longer feel the effects, your body may still contain detectable levels of drugs. During this time, you remain unsafe — and illegal — to drive.
Drug-Related Crash Statistics
Over the past five years, about 41% of drivers and riders killed on Victorian roads who were tested had drugs in their system.
- Cannabis and stimulants are the most common substances detected.
- 1 in 4 drug users in Victoria admit to driving under the influence of drugs.
- In 2018, 19% of driver and rider deaths involved drugs — with 10.3% linked to cannabis.
- The number of roadside drug tests conducted by Victoria Police rose from 40,000 in 2014 to 150,000 in 2019.
Drug testing is carried out using alcohol and drug buses, marked and unmarked patrol cars, motorcycles, and mobile intercept units.
Why Driving While High Is Dangerous
Driving under the influence of drugs — whether illegal substances or prescription medication — puts everyone on the road at risk.
Drugs can impair judgment, coordination, perception, and reaction time.
Even prescription medicines can affect driving ability. If you’re unsure whether your medication could impair your driving, consult your doctor or pharmacist.
Although fatalities from drink-driving have declined, drug-driving deaths have risen in Victoria.
How Drugs Affect Driving
Different drugs impair driving in different ways — and mixing them can make effects even more dangerous.
- Cannabis – Slows reaction time, affects concentration, and distorts perception of time and distance.
- Heroin – Causes drowsiness, confusion, and impaired spatial awareness, making vehicle control difficult.
- Methamphetamine (ice), ecstasy, cocaine – Boost confidence and risk-taking, then cause fatigue and poor focus when effects wear off.
- Hallucinogens – Distort time, space, and movement perception; may cause hallucinations.
- Polydrug use (multiple substances) – Severely impairs coordination, focus, and decision-making.
How to Keep Yourself Safe
The safest approach is simple: never drive with alcohol or drugs in your system.
Even if you feel fine, traces of drugs can remain in your body for hours or days.
If you’re unsure whether you’re fit to drive, choose a safer alternative — call a friend, book a taxi, or use public transport. It’s never worth the risk.
Penalties for Drug-Driving
You may face serious penalties for:
- Failing a roadside drug test.
- Driving under the influence of drugs.
- Refusing to take a drug or impairment test when asked by police.
Penalties can include:
- Large fines.
- Licence suspension or disqualification.
- Criminal charges for repeat or combined drug-and-alcohol offences.
- Vehicle impoundment or confiscation for serious or repeated offences.
If you receive a drug-driving infringement but someone else was driving your vehicle, you may be able to dispute the fine by nominating the correct driver. Ensuring the right person is identified is essential, as failing to nominate can result in additional penalties and licence consequences.
Conclusion
Roadside drug testing in Victoria plays a crucial role in keeping roads safe.
These tests detect drugs that impair a driver’s ability to control a vehicle safely — even in small amounts.
Drug-driving can have life-altering consequences: from licence loss and fines to criminal charges or fatal crashes.
If you plan to drive, stay drug-free.
And if you’re unsure whether a substance — legal or illegal — affects your driving, always seek professional advice before getting behind the wheel.
