Back in 2001, Canada was the first nation to legalize marijuana for medical use after the Canadian Court of Appeal declared medical pot prohibition unconstitutional. Recently, the federal government promised to introduce legislation to legalize cannabis for recreational purposes in the next spring.
However, there are no further details on what the legislation might look like, which leaves many questions unanswered. And road safety seems to be one of the most important gray zones in this matter.
As the government eases cannabis laws, it presents a significant challenge to law enforcement to keep the roads safe from drugged drivers. Numerous road safety advocates claim that the highway rules for driving under the influence of marijuana are lagging, and that would increase the number of fatal crashes on the Canadian roads.
When Colorado legalized recreational marijuana in 2014, it faced the same difficulty: the state's police were not prepared to crack down on those who consume marijuana before getting behind the wheel.
The maximum allowed amount of marijuana in the user's blood has not been determined yet because weed affects people in a way different from any other drug or alcohol. In order to determine the critical level of the psychoactive component, adequate studies must be conducted, since as of today, there is an insufficient amount of information on the matter.
In Colorado, for example, it is legal to drive with up to five nanograms of active THC per milliliter in blood. Although, no matter what level of THC was detected, you can still be arrested. Washington has also set the same intoxication limit. However, the data shows that marijuana-related accidents could be caused by any level of marijuana in the driver's system, although that does not necessarily mean that pot causes or even contributes to accidents, fatalities, or traffic violations.
So far, there is nothing that can help prevent weed-related trouble on the roads: no hand-held device that police officers can use, no standard cannabis limit. However, The Colorado State Patrol is using marijuana DUI devices—oral fluid testers that sample a driver's saliva for the presence of drugs. Canada is currently exploring the use of similar DUI devices on its roads.
At the same time, many specialists claim that while oral sample THC testing can give good results in the lab, the same method becomes useless at the roadside.
Police admit that until the legalization is enacted, their officers will find themselves in a pretty awkward position.
The problem is that on the roads, it is possible to test only for the presence of cannabis metabolites, not for intoxication. The decades of experience in setting limits for alcohol turned out to be rather useless because the mind-alerting compound in marijuana, THC, is fat-soluble while alcohol dissolves in water. That means that measuring the level of alcohol in one part of the body can predictably tell the police officer how much alcohol there is in any other part of the driver's body. The situation with marijuana is absolutely different: THC can still be found in the system even when it is no longer measurable in the blood. And vice versa, regular cannabis users can sometimes have THC levels above the legal limit but still drive well.
That is why it is crucial to have a clear way to determine the critical level of marijuana intoxication for drivers to be able to drive a vehicle.