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DWI vs DUI: What is the difference?

DWI vs DUI: What is the difference?

If you have been charged with an impaired driving offence, you have likely heard the terms “driving under the influence” (DUI) or “driving while impaired” (DWI). At this point, you might be wondering, what do these phrases actually mean? Both terms refer to driving a vehicle while under the influence of alcohol, drugs, or both. While both terms describe impaired driving in this sense, “DUI” is most often used in the United States while the Canadian offence is generally described as “driving while impaired”.

In this article, we will help you better understand what “driving while impaired” means in terms of the offences contained in the Criminal Code.

Firstly, it is a criminal offence to operate a vehicle while your ability to do so is impaired by drugs and/or alcohol to any degree. This means that the police is not required to provide evidence that you had a specific alcohol or drug concentration in your blood. All that is necessary is proof that you:

  • operated the vehicle;
  • had consumed alcohol or drugs; and
  • the alcohol or drugs impaired your ability to drive.

In these cases, police may rely upon what they see rather than a blood or breath sample. These observations may be used to prove that your ability to operate was impaired by drugs and/or alcohol. Examples include (but are not limited to) whether your eyes are bloodshot, whether you are unsteady on your feet or unable to walk straight, or erratic driving patterns. 

The term, “operating” a vehicle, is not limited to driving. If you are considered to have care or control over the vehicle while your ability to drive has been impaired by alcohol or drugs, this may be enough to ground a conviction—even if you aren’t actively driving or intending to drive. 

The second type of offence is based on an actual blood or breath sample rather than simply observing you or your ability to drive. It is an offence to operate a vehicle while your blood alcohol concentration or blood drug concentration is higher than the legal limit within two hours since you stopped operating the vehicle. 

For alcohol, the legal limit is equal to or more than 80 mg of alcohol in 100mL of blood. 

For Cannabis, there are two different offences for differing concentration levels:

    • Between 2 nanograms (ng) and 5 ng of THC per mL of blood; or
    • 5 ng of THC or more per mL of blood. 

Any detectable amount of LSD, psilocybin, psilocin, ketamine, PCP, cocaine, methamphetamine or 6-mam in your system would be an offence, and the prohibited level for GHB is 5mg or more per litre of blood. 

The legal limit when alcohol and cannabis are combined is 50mg or more of alcohol per 100mL of blood and 2.5ng or more of THC per mL of blood. 

Importantly, the two-hour time period means that if your blood concentration shows illegal alcohol or drug levels, you can be charged even after you stop driving. There is an important exception to this rule if:

  • you consumed alcohol or drugs after you stopped operating the vehicle;
  • you had no reasonable expectation that you would be required to provide a blood or breath sample; and (if you are drinking alcohol)
  • your alcohol consumption is consistent with a blood alcohol level that would have been less than the legal limit when you were driving. 

If you are convicted of an impaired driving offence, you may face a hefty fine, license suspension, or a jail sentence depending on the circumstances. 

As of December 1, 2020, Peace Officers in Alberta have authority to charge a suspected impaired driver under the Traffic Safety Act and impose an immediate roadside suspension (IRS), rather than laying criminal charges. If you are subject to an IRS under the Traffic Safety Act, you have only 7 days from the date of the incident to file an appeal of your license suspension. 

If you are charged with an impaired driving offence or subject to an immediate roadside suspension, it is important that you speak to a lawyer as soon as possible in order to understand the legal consequences and present the strongest defence possible.