Does Impaired Driving Reflect Impaired Learning?

If you’ve ever driven when really tired, or been in a car with a driver who’s really tired, you know what “impaired driving” feels or looks like. (For those who don’t: in a nutshell, it’s kind of scary.) Chances are, though, you don’t think of being tired as something bad. Instead, you know that being tired means you should be in bed, recuperating by sleeping for a while.

Drug-impaired driving is much the same thing. It’s less about whether a drug is good or bad, and more about where you are when you’re feeling a drug’s full effects. While avoiding intoxication may be the best option with any psychoactive drug, if it happens, the safest place to be enjoying or reversing the buzz is at home, at a pal’s house or in the back of a taxi or sober person’s vehicle. Almost anywhere but behind the wheel.

Even though we all know we shouldn’t drive impaired, it still happens.

  • In 2012, 6.5% of BC drivers tested positive for alcohol, and 7.4% tested positive for other drugs, cannabis and cocaine being the most commonly detected substances, according to a roadside survey report.
  • ICBC reports drug impairment (involving alcohol, illegal drugs and medications) was the key factor in 23% of fatal car crashes in 2013 (speed was key in 28%, and distraction in 29%).
  • Over the last five years, an average of 86 people per year lost their lives in impaired driving crashes on BC roads.

So, what’s going on with us? What narratives are running through our heads about our rights and responsibilities as drivers? What are the best ways to change some of our beliefs and behaviours? These are the kinds of questions we not only need to be asking ourselves, but should also form the foundation of our drug education programs in schools.

Instead, most of the conversations we have with young people about drugs are not really conversations at all, but lectures aimed at scaring students into saying whatever the adults in the room want to hear. The problem with this approach is that it isn’t working. Young people, particularly young males, continue to make up the bulk of those taking unnecessary risks with substances and vehicles. We should be wondering why, and we should be talking to students more often about the things that drive their decisions to drive under the influence.

A cartoon image of a brain listing different types of impairments
A screenshot from the drugsanddriving.ca website.

Honest, open and real conversation about alcohol and other drugs is one of the goals of Drugs and Driving, a project involving a range of classroom learning activities, a variety of web apps, and even a free iPhone app. Drugs and Driving is designed for Grade 10 students but can be used in other grades as well. The program is less about telling kids about the dangers of drugs and driving and more about helping them reflect on a range of issues related to impairment. What are the things that might cause impairment? How do I know if I am impaired? Why should I care? How do we make decisions? How can I influence the decisions of my peers? These are important questions for all of us.

Bodner Nicole-

Author: Nicole Bodner, Centre for Addictions Research of BC

**Please note that the material presented here does not necessarily imply endorsement or agreement by individuals at the Centre for Addictions Research of BC.

Driving under the influence of cannabis

Attitudes toward driving under the influence of cannabis vary greatly. Some individuals claim that driving under the influence is extremely dangerous; whereas others suggest that cannabis is a fairly innocuous substance that does not increase your risk of collisions.  Research indicates that the true answer is somewhere between these two extremes. Comparisons between studies of alcohol intoxication and collision risk versus studies of cannabis intoxication and collision risk show that alcohol has more detrimental effects on driving than cannabis has on driving. Conversely, some research has shown that drivers under the influence of high levels of cannabis attempt to compensate for their condition by driving slowly and cautiously. However, while compensation can help reduce the risks of collision, these risks are not fully eliminated.

A recent review of the evidence showed that cannabis doubled the likelihood of a collision, which would be similar to the likelihood of collision from having a blood alcohol content (BAC) of .05%, the legal alcohol limit in most Canadian provinces.  For comparison, heavy alcohol intoxication to a BAC of .20% alcohol is related to over an 80 fold increased likelihood of a collision. Cannabis affects your attention span making it harder to concentrate on driving and makes it difficult to shift attention to deal with changes in the environment. Evidence suggests cannabis may also impair tracking ability (i.e., harder to follow your lane), and sense of time and distance.  The duration of impairment from cannabis lasts on average about 90 minutes, but it is best not to drive within 4 hours after smoking cannabis.

It is a criminal offense to drive under the influence of cannabis, however, nearly half a million Canadians admitted to driving within two hours of using marijuana or hashish in 2006 and youth report driving after cannabis more than after alcohol (40% vs. 20%). If a police officer suspects that you are driving while under the influence of cannabis, you can be sent to the police station for examination of impairment by a drug recognition expert, and possibly be asked to provide a biological specimen, such as urine or blood for analysis. This process is time consuming and cumbersome for the police. Some countries have dealt with the issue by implementing roadside saliva testing – a test that can detect the use of cannabis over the past few days. For example, Australia has a zero tolerance policy for driving under the influence of cannabis and uses roadside saliva tests to assess for the presence of THC. However, saliva and urine tests are not as effective at detecting impairment compared with the Breathalyzer test used for alcohol, where increased blood alcohol concentration corresponds closely with safety risk. That is, a person who tests positive for cannabis on a saliva or urine test may not be under the influence at the time of the test and therefore their driving may not be impaired. Another more accurate option for detecting cannabis impairment is the use of blood tests, currently being used in Germany, however these tests are also more intrusive and difficult to implement at roadside.

Driving under the influence of cannabis is a serious public health concern and with the recent legalization of cannabis in Washington State and Colorado and the continued movement towards decriminalization of cannabis in BC, cannabis related driving policies will be an important component of any regulatory system. 

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Authors: Scott MacDonald, Assistant Director, CARBC, and Chantele Joordens, Research Associate, CARBC