Takin’ it to the streets: impaired driving in light of legalizing marijuana

Impaired driving is a very complicated area of the law. It has received a great deal of attention in the media in recent decades, but most people think of impaired driving as simply “drunk driving.” However, impaired driving laws apply to much more than just situations of drunk driving. Impairment by any drug—including prescription drugs and recreational drugs like marijuana—can also lead to impaired driving convictions.

On October 19, Canadians elected a Liberal majority government led by Justin Trudeau. One of the Liberals’ many pledges was to “remove marijuana consumption and incidental possession from the Criminal Code, and create new, stronger laws to punish more severely those who provide it to minors, those who operate a motor vehicle while under its influence, and those who sell it ourside of the new regulatory framework”

(https://www.liberal.ca/realchange/marijuana/) . (It is worth noting that it is the Controlled Drugs and Substances Act (“CDSA”)—rather than the Criminal Code—which currently makes the possession of marijuana a criminal offence…)

While legalizing possession would certainly make life easier for marijuana users, it is important to bear in mind the problem of impaired driving—especially in relation to marijuana use.

Section 253(1)(a) of the Criminal Code currently makes it an offence to operate or have care or control of a motor vehicle “while the person’s ability to operate the vehicle…is impaired by alcohol or a drug” (s. 253(1)(a) of the Criminal Code of Canada).

In order to prove an impaired driving charge, the Crown does not have to provide any evidence of bad driving (see, for example: R v Polturak (1988), 9 MVR (2d) 89 (Alta CA)). This is because the focus of the charge is on an individual’s state or ability to drive as opposed to whether there was actually anything wrong with the accused’s driving at the time of the incident. In fact, an individual does not even need to have been driving—simply being behind the wheel of a parked vehicle, where care or control is made out, after consuming alcohol or drugs can lead to a conviction under this section.

Although in order to convict an individual of impaired driving, the judge must be satisfied of that person’s guilt beyond a reasonable doubt, it is vital to remember that the courts have said, “If the evidence of impairment establishes any degree of impairment ranging from slight to great, the offence has been made out” (R v Stellato (1993), 18 CR (4th) 127 (Ont CA)).

Cases of impaired driving involving drugs are often even more complex than drunk driving cases. In most drunk driving cases, an accused individual stands charged of both impaired driving (as discussed, under s. 253(1)(a)) and “driving over 80” (under s. 253(1)(b)). Section 253(1)(b) essentially deems that anyone with more than 80 milligrams of alcohol per 100 millilitres of blood is “impaired” for the purposes of the laws against impaired driving. Measurement of blood-alcohol content is typically obtained through breath samples provided into a machine like a breathalyzer.

With “drugged driving” cases, however, testing becomes a significant issue. As of now, Canada has not implemented anything similar to a simple test involving a machine like a breathalyzer. Instead, at present, certain police officers with specialized training—called “drug recognition experts” (“DREs”)—conduct a number of tests and evaluations (including eye examinations, balance and coordination testing, physical measurements and observations, etc.) and render an opinion as to whether a person is impaired by any drugs. Urine or blood samples are then demanded and these are sent to a lab for forensic analysis by an expert. However, the forensic expert merely analyzes the samples for the presence of substances; forensic reports do not typically list concentrations of particular drugs. Because certain drugs can be detected in a person’s system long after the impairing effects of those drugs have passed, this can be quite problematic. A positive urine or blood test result is not by itself enough to show impairment, but it certainly can be in conjunction with a DRE report.

Without changes to impaired driving laws to account for individuals driving under the influence of drugs generally and marijuana specifically, especially in light of a proposal to legalize marijuana, drugged driving cases will continue to be quite difficult—for both prosecutors and defence lawyers. Reports and opinions from DREs are just as important to drugged driving cases as breathalyzer results are to drunk driving cases; this poses a significant challenge as human beings are typically not as reliable or accurate as machines. It may be time to consider taking a similar approach to drugged driving as the “over 80” approach to drunk driving; by setting a “deemed impairment” limit in relation to active tetrahydrocannabinol (“THC”), the government could ensure that there is more certainty in this area of the law. At present, there is very little. It will be interesting to see how the Liberal government will alter impaired driving laws.


About Brandon Trask

Brandon Trask is a regular blog contributor and former colleague of Daniel Murphy and currently a doctoral student at the University of Toronto’s Faculty of Law. He was formerly a Crown Attorney in Newfoundland and Labrador. Brandon holds law degrees from the University of Manitoba and the University of Toronto.