The federal task force on legalizing marijuana says the Liberal government must launch a public awareness blitz and boost spending on police training and tools to keep pot-impaired drivers off the roads.

Anne McLellan, a former cabinet minister who chaired the task force, said Canadians are now routinely charged and convicted of drug-impaired driving. But she said right now, there is no reliable, proven roadside test for marijuana intoxication.

"Drug-impaired driving is a problem, is a challenge, here in Canada today," she said. "That is why the science is very quickly catching up. But are we there yet? No."

McLellan said the RCMP, OPP and other police forces across Canada are currently trying out roadside testing devices to determine which one, if any, might be the "breakthrough."

Right now, officers can carry out a standardized field sobriety test, and if they suspect a driver is impaired they can call for an additional evaluation by a drug recognition expert who is properly trained and better able to detect impairment.

Roadside saliva tests

But Andy Murie, chief executive officer of MADD Canada, said while there is no precision around testing impairment levels for marijuana, roadside saliva tests have proven effective in Europe and Australia. Even the current levels for alcohol are "somewhat arbitrary" and limits for pot could be set within a range, he said.

Murie said there should be a zero tolerance policy for young drivers. A failure to put proper rules and enforcement measures in place could prove deadly, he warned.

"If they don't have the driving piece nailed down before you start retail sales of cannabis, you're just going to kill a whole bunch more young people on the road," he said.

On Wednesday, Public Safety Minister Ralph Goodale said municipal and provincial police forces, as well as the RCMP, will carry out tests in seven locations across the country on two pieces of equipment beginning this month. The goal is to measure the effectiveness and reliability of the technology and tests, including in Canadian cold weather conditions.

Goodale believes they will get a good sampling, even though participation would be voluntary.

"It's not something that could be demanded as a mandatory order," he said. "In order for the equipment to be used in real-life circumstances, there would have to be changes in the law."

Relying on people who provide their consent is the only way to proceed to determine if the machines work, he insisted.

MADD Canada warns there could be more drug-driving impaired deaths without proper measures to keep stoned drivers off the roads. (Glen Kugelstadt/CBC)

Mario Harel, president of the Canadian Association of Chiefs of Police, was pleased the report flagged the concerns of law enforcement officers, who have called for more tools and training. But he said there are still no answers on detection practices as the government prepares to table legislation in the spring.

"There are still a lot of questions on how they are going to determine what impairment is for the drivers," he said.

Senate Opposition leader Claude Carignan tabled a private member's bill this fall designed to stop drug-impaired drivers from getting behind the wheel.

At the time, he described it as a growing problem that goes largely unreported because of a lack of roadside measurement devices. Of all impaired driving charges, he said 97 per cent are for alcohol and only three per cent for drugs and warned the dire situation could become "catastrophic" when marijuana is legalized.

'No good test'

Conservative health critic Collin Carrie echoed those concerns today, insisting the government has no strategy to prevent pot-impaired drivers of vehicles or heavy equipment.

"There's no good test out there," he said, adding that the main "deterrent" right now is that marijuana is illegal.

NDP critic Murray Rankin said the task force report provides some guidance and contains "intriguing ideas" for legislation that could work for Canadians. But he said the impaired driving issue remains a big concern.

"It depends on body weight, it depends on time of consumption, it depends on the THC content of what you've smoked," he said. "The problem is we don't have a good idea, and that's why police in different jurisdictions are particularly concerned about how they're going to address the issue of stoned drivers."

The task force report says the issue of pot-impaired driving generated "a great deal of concern and discussion" during the panel's extensive six-month consultation. It said cannabis-impaired driving is "more complex" to study than alcohol-impaired driving, and recommends a public awareness campaign and greater investment in both research and training and tools for police.

Anne McLellan, the Chair of the Task Force on Cannabis Legalization and Regulation, says that education - like that around drunk driving - needs to be part of any marijuana legislation. 2:51

Among the task force's findings on pot-impaired driving:

While scientists agree THC (tetrahydrocannabinol) impairs driving performance, the level of THC in bodily fluids cannot be used to reliably indicate the degree of impairment or crash risk.

While there is an established metric for alcohol intoxication, there isn't one for cannabis.

In contrast to alcohol, THC can remain in the brain and body of chronic, heavy users of cannabis for prolonged periods of time, possibly leading to a level of chronic impairment.

Some heavy, regular users of cannabis, including those who use it for medical purposes, may not show any obvious signs of impairment even with significant THC concentrations in their blood.

There is a significant combination effect when cannabis is consumed with alcohol, leading to a greater level of intoxication and motor control problems than when either substance is consumed alone

Roadside testing tools to measure THC presence in a driver's system are "in development." Oral fluid screening devices are the most advanced today, and have the added advantage of signalling recent use.

recent use. Other challenges exist, including the need to account for the rapid and sharp decline of THC levels in the blood in the hours following consumption through smoking; with edibles the decline is more gradual.