Windsor's Mothers Against Drunk Driving representative wants police in the area to have permission to test the saliva of drivers to determine whether or not they are under the influence of marijuana.

Officers currently rely on the actions of drivers to determine whether they have been using the drug.

Chaouki Hamka, community leader for MADD Windsor Essex County, said police should be allowed to use saliva swabs during roadside tests to determine if someone is driving while stoned.

"Having random breath testing gives the police an alternative tool to crack down on impaired driving, especially when you're under the influence of marijuana," said Hamka. "Too many people are going undetected."

Hamka expects the number of people driving while under the influence of marijuana will go up once it is legalized next year.

Chaouki Hamka, community leader for MADD Windsor Essex County. (Dale Molnar/CBC)

Medical marijuana smoker Kevin Smith said he knows people who do smoke marijuana and drive, but he's against it.

"Me as a medical patient I don't agree with it. It's just a no-no," he said. "You don't drive and operate a vehicle. Period."

The question of whether or not someone who has used marijuana is able to drive can be tricky for police, said Const. Shane Miles, drug recognition expert with Windsor Police.

"The unfortunate part about impairment is that it is very subjective and it's based on a reduction in inhibitions, or an effect on you physiologically as a result of the drug," he explained.

Driving stoned is dangerous

Those factors also make it difficult for police to obtain convictions in cases where they believe a driver was using drugs, said defence lawyer Brian Ducharme.

"There is no scientific test to determine if you have sufficient marijuana in your body other than a blood test," said Ducharme, who defends those accused of impaired driving. "But as I understand it, it's just not practical in most cases for the police to get blood evidence."

Still, Miles has a warning for those who believe they can use marijuana and drive — they are kidding themselves and risking lives if they do.