Police chiefs from across the country are in Montreal this week and among their concerns is the impending legalization of marijuana.

Mario Harel of the Canadian Association of Chiefs of Police said officers are concerned about people driving while high.

"Obviously with the legalization of marijuana we anticipate more encounters with people under the influence of marijuana while driving," said Harel.

In anticipation, police are testing new equipment to detect the presence of marijuana use in drivers.

Officers in Gatineau tested several machines and said they found two problems: the cost per sample was $40, thus making testing prohibitively expensive, and the machines used did not perform well in the cold.

"What the CACP [has been asking] for, since the beginning of the discussion of the legalization of marijuana is the need for training our officers, the need for equipment to detect drivers under the influence," said Harel.

Studies show that people who use marijuana have delayed reaction times and are more likely to 'weave' while driving, and this tendency increases if a driver uses alcohol at the same time -- even if below the legal limit for alcohol impairment.

In Quebec, the SAAQ has launched advertising campaigns to warn people about impaired driving due to marijuana, and Harel said police would like to see more such campaigns in the months and years to come.

Harel said police are lobbying federal and provincial governments to take that into account before marijuana starts being sold.

"I know we are working in a short amount of time right now but we've been having some talks with our government leaders," said Harel.

Mothers Against Drunk Driving feels police must have the right tools at their disposal before pot is legalized, slated to happen by July 1, 2018.

“Eighty per cent of kids are admitting to get into a car with a friend who has smoked pot an hour after the friend has smoked. They don't think it's dangerous,” said MADD spokesperson Theresa-Anne Kramer.

MADD is calling on various levels to have awareness campaign about the risks of driving stoned.

Police agree it's necessary.

“I think people don't understand the effects marijuana and how long it stays in the system. It's very different than alcohol and that's why we need with the data,” said Harel. “We need to educate people.”