Victorian medicinal cannabis users free to drive from today

Victorian medicinal cannabis users will no longer automatically lose their licence if they're caught driving with traces of the drug in their system from today.

Drivers who test positive in a random roadside test for cannabis will have the opportunity to appear in court and present their prescription.

Magistrates will have the power to use their discretion when sentencing people who have tested positive for tetrahydrocannabinol (THC).

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About 1.8 million medicinal cannabis prescriptions have been issued since 2016.

Legalise Cannabis Victoria MP David Ettershank said it was a victory for common sense.

"Until now anyone prescribed medicinal cannabis lived in fear of losing their licence because under the old laws even trace amounts of THC resulted in a six-month loss of licence for a first offence and Victorian magistrates had no power to intervene," je he said.

"From March 1, magistrates have the power to say, 'You are a medicinal cannabis patient, you have provided your current script, and you weren't impaired behind the wheel – you can keep your licence.'"

THC, the psychoactive component of cannabis, can remain in a person's system for several days after they take their prescribed medication.

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Fellow Legalise Cannabis Victoria MP Rachel Payne said the law change was much needed.

"THC is only impairing for a few hours, but a saliva test will come up positive to THC days after consumption," Payne said.

"I am prescribed medicinal cannabis and like other patients, I am responsible and never drive in the hours after taking my medication, but I live in fear of being stopped by police and testing positive.

"There could be tiny traces of THC in my system. I just don't know, but I'm so relieved that I will now be spared from automatic loss of licence."

The government has invested $4.9 million for Swinburne University to quantify the drug's intoxication.

Researchers over the year will put a total of 96 drivers to the test to measure differences in speed, control, steering, braking and a driver's ability to handle distractions while using medicinal marijuana.

They will then hand down a report later this year, which may include some recommendations.

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