The challenges of policing drivers impaired by pot use

The use of recreational marijuana is expected to be legalized this summer, but new rules regarding driving while high aren’t expected to come into effect fully until at least December.

In the interim, police forces across the country are scrambling to get officers trained to spot drivers impaired by pot use. The Toronto police service currently has only 15 trained drug recognition experts (DRE).

While more officers are being trained, the program is lengthy, complex and requires learning how to execute a battery of tests, including the collection of toxicology samples.

Const. Clint Stibbe says Toronto police has been preparing for the legalization of marijuana for some time and has trained hundreds of officers on delivering basic, standardized field sobriety tests.

“They do have the tools in order to place a person under arrest based on the criminal code … that may be impaired by a drug, an alcohol or a combination of the two,” he says.

Bill C-46, currently before the senate, aims to give officers more tools to detect drug use. It sets out new thresholds for THC levels — the psychoactive element in pot — while driving. If the bill passes, DREs are expected to be called on more frequently.

Drivers would be tested with oral swabs to detect how much THC is present in their systems. However, THC levels are not an accurate indicator of how impaired a person might be. An individual’s tolerance level, method of consumption and even metabolic rate could impact their actual level of impairment.

“We need to keep in mind that how everybody reacts to that, what they consume and what the officer is faced with will be unique on a case by case basis,” Stibbe says.

MADD Canada says the variable impact of THC levels on impairment is why they aren’t in favour of an ‘absolute zero’ approach.

“You have to allow some margin of error for these instruments to measure against,” says Andrew Murei, CEO, MADD Canada. “If you simply use zero, you might be picking people up that have a drug in their body, but it has no effect on their driving ability”

The senate committee returns to the bill later this May.