Pot presents unique dangers when driving under its influence
Cannabis affects drivers’ perception of time and space, writes
On Oct. 17, 2018, the sky will fall — in Canada. That’s according to the anti-pot legalization crew, anyway. They are predicting that chaos — in the form of some ground up bud rolled into a small cigarette — will be unleashed on our roadways.
A recent Statistics Canada survey reveals nearly 16 per cent of Canadians have consumed some form of cannabis in the past three months. Guess what? Lots of Canadians smoke weed, and the sky is still intact.
Dr. Andrea Furlan, an associate doctor of medicine at the University of Toronto and a Toronto Rehab Foundation scientist, isn’t panicking. Furlan has done extensive work with opioids and medical marijuana, and her work with Toronto Rehab allows for as close to real-world experimentation as you can get; the iDAPT DriverLab is one of the best driving simulators in the world.
She’s quick to note that pot isn’t alcohol, and both users and the legal system will have some growing pains if they try to use one template for the other.
“Alcohol and cannabis affect different parts of the brain. Those who consume alcohol and get behind the wheel are more likely to take greater risks, to be aggressive. Cannabis slows you down. We see people driving more slowly and leaving greater distances between themselves and other drivers,” she explains.
Sounds almost like a good thing, given the number of tailgaters, no?
No. According to Furlan, “when these drugs are used socially, we tend to see people using them together. Because they work on different parts of the brain, differently, there can be impairment even if both “legal” levels for alcohol and cannabis are within accepted levels.”
This will be the tricky road that police and the courts will be navigating. A police officer I spoke to about the subject chose his words carefully, reminding me that police are looking for impairment of that individual driver’s inability to safely and legally operate a vehicle.
We will still be seeing roadside sobriety tests — standing on one leg, walking and turning, finding your nose with your finger — though Canada is also set to roll out the saliva-test kits they tested last year. A spit test will show signs of the Big Six most commonly abused drugs: cannabis, amphetamines, methamphetamines, cocaine, opiates and benzodiazepines.
If you’ve ever been drunk, you know how long until it clears your system. I’ve seen RIDE checks operating at 7 a.m. around holidays, because officers know there are still drivers with high enough blood-alcohol levels to zing the machine.
Furlan’s research points to another wrinkle in the testing for, and preventing abuse of, pot.
“Cannabis has many strains, and many medical indications. It can be smoked or ingested, and it’s stored in the body in adipose tissue. Whereas establishing 0.08 ( blood-alcohol limit) as impaired for alcohol consumption is fairly straightforward, there are many factors that complicate a similar measure for cannabis.”
The patients Furlan prescribes medical marijuana for would necessarily have the presence of the drug register in their systems, though it is unlikely it would be at the level of impairment. She still tells them not to drive for four hours after their last toke, and warns them their charts indicate that warning in case they think she’ll back them up for abusing the drug in the event of a collision.
The Stats Can study that reveals that 16 per cent of Canadians have used cannabis didn’t surprise her, but the fact that one in seven of those users had got behind the wheel within two hours of using, did.
“We have to bring science to this discussion, especially with younger drivers. They think that because they’re more relaxed, they’re better drivers when they smoke or ingest cannabis. Younger drivers tend to think that because it’s legal, it’s safe.”
Your pot-addled brain may mean you drive slower and leave more distance ahead of you, but it also distorts your perception of time and space. Your response time is bad, though your judgment is not impaired; you know you’re impaired. Alcohol is the flip side of the coin: it impairs your judgment, so you do not believe you are impaired. Furlan’s warning about the popularity of combining the use of the two drugs is where communities (citizens, police, legal) will have to find a way to recognize impairment, not just levels of presence.
Furlan and her colleagues will continue to do work with the iDAPT DriverLab, where they can test the impact of the many uses of cannabis for pain management, as well as recreational use.
This is how she prioritizes her message: Just because cannabis is legal, like alcohol, its sale and use will be controlled and monitored for a reason.
Because so many people combine the two substances, they should be aware that while technically registering within ‘safe’ legal zones on both products, they can still be — and be found to be — impaired. An officer is considered an expert witness in a court of law.
Those consuming cannabis for medical purposes should heed their doctor’s direction on safety regarding driving, though they are unlikely to be considered impaired under normal circumstances, just as with other pharmaceutical drugs.
Testing of body fluids for detection of cannabis is not as straightforward as testing for blood-alcohol concentration.
Do not drive for at least four hours after your last toke, or for 12 hours after you’ve ingested edibles. If you’re loopy or tired, don’t drive at all.
Although cannabis doesn’t impair a driver’s judgment the way alcohol does, the drug does slow the response time of users who are under its effects.