Updated: October 20, 2026
Legally Reviewed by Alan Pearse
You smoked a joint hours ago, well before you got behind the wheel, and you feel completely fine driving home
from your friend’s place. The officer on Deerfoot Trail doesn’t see it that way. He mentions your eyes, asks if you’ve used any cannabis today, and now you’re doing roadside tests for something you thought had worn off a long time ago. You didn’t think ther
e was still anything in your system that would show up, but you don’t know how long is actually long enough.
Alan Pearse understands how little clear guidance exists around cannabis and other drugs and driving, and he can help you understand what you’re facing with a DUI for drugs charge and how impairment actually gets measured.
What Counts As DUI Drug Charges in Calgary?
In Canada, driving while impaired by a drug is a criminal offence under the same impaired operation provisions that criminalize impaired driving by alcohol. An officer’s observations, a drug recognition evaluation, or a blood test can each provide evidence supporting a charge, meaning a case in Calgary can start with far less evidence than most drivers expect.
How Do Calgary Police Test for Drug Impairment?
A Calgary officer who reasonably suspects drug use can demand a physical coordination test at the roadside or a saliva sample analyzed through one of only two approved devices in the country, the Dräger DrugTest 5000 and the Abbott SoToxa system. Both devices flag common drugs, including cannabis and cocaine, within minutes at the roadside. A positive result does not end the investigation. It can give the officer grounds to take the next step.
What Happens After a Positive Roadside Screen?
The Drug Recognition Evaluation
Once a saliva screen or an officer’s own observations provide reasonable grounds to believe that a driver is impaired by drugs, a driver may be required to submit to an evaluation by a specially trained evaluator at the station. That officer works through a structured process designed to identify which category of drug, from cannabis to opioids to stimulants, appears to be affecting the driver.
The Follow-Up Sample
If the evaluation indicates impairment by a particular drug, the officer can then demand a further sample of oral fluid, urine, or blood to confirm the drug’s presence and, if blood is taken, measure its concentration. That sample, along with the evaluation and the officer’s observations, can become important evidence in the Crown’s case.
Why Does One Traffic Stop Turn Into Two Separate Cases?
In Alberta, a failed drug recognition evaluation or a refusal also triggers an Immediate Roadside Sanction, a provincial administrative penalty that lands before the criminal case ever reaches a courtroom.
A first sanction begins with 90 days during which a driver cannot legally drive under any circumstances, followed by a further 12-month licence suspension, eligibility for Alberta’s Ignition Interlock Program, a 30-day vehicle seizure, and a $1,000 administrative penalty plus a 20% surcharge. None of that depends on a conviction. Challenging the notice is its own narrow process: a driver has 7 days to request a review, the review itself costs a non-refundable $150, and the suspension and seizure stay in effect while it is pending.
Which Drugs Lead to a Drug-Impaired Driving Charge?
A DUI for drugs case in Calgary is not limited to cannabis, and federal regulations prescribe concentration limits for cannabis and several other drugs:
- 2 or more but less than 5 nanograms of tetrahydrocannabinol, or THC, per millilitre of blood supports a less serious, summary-only charge;
- 5 nanograms of THC or more supports a more serious charge that the Crown can pursue either way;
- 2.5 nanograms of THC combined with 50 milligrams of alcohol per 100 millilitres of blood supports a combined alcohol and drug charge; and
- Several other listed drugs, including cocaine, methamphetamine, and ketamine, can support a charge with any detectable level.
Drugs without a prescribed concentration can still support a charge if the Crown proves impairment.
Refusing to comply with a testing or evaluation demand is its own offence, often easier for the Crown to prove than impairment itself. For a concentration-based offence, the law also provides an exception for a drug consumed only after a driver stopped driving, provided there was no reasonable expectation of being tested.
What Are the Criminal Penalties for a Drug-Impaired Driving Conviction?
Except for the lower-level THC offence involving 2 or more but less than 5 nanograms per millilitre, a criminal conviction under the drug-impaired driving provisions discussed above carries penalties that grow more serious with each offence:
- A first offence carries a mandatory minimum fine of $1,000;
- A second offence carries a mandatory minimum of 30 days in jail;
- A third or later offence carries a mandatory minimum of 120 days in jail; and
- Each of these offences remains eligible for up to 10 years’ imprisonment when the Crown proceeds by indictment.
These are floors, not ceilings, and a court can add a lengthy driving prohibition and other conditions on top of them.
A Lawyer Focused on Impaired Driving Since 2000
Mr. Pearse has practiced impaired driving law since 2000, a focus that has carried him through more than 2,000 cases across the country. He tries every one of those cases himself; a file never moves to another lawyer partway through.
That depth of focus is why organizations like the Canadian Bar Association bring him in for input on impaired driving policy, why he has authored position papers in that capacity, and why other lawyers across Canada regularly bring him their toughest questions on the subject. He can appear in courts in every province and territory, so a Calgary case draws on the same command of the law he brings to a courtroom in Yellowknife or Regina.
Your Next Step Starts with a Conversation
A DUI for drugs charge moves fast, and the roadside sanction clock does not wait for anyone to feel ready. Reach out to talk through your situation directly with Mr. Pearse, day or night; he answers texts around the clock for exactly this reason. The sooner he understands what happened at the roadside, the more options remain open for how the case gets handled.
Contact Us 24/7
If you have been charged with Driving Under the Influence of Marijuana in Calgary and Alberta, call 1-866-912-3560 or contact us today! Our legal team has defended thousands of impaired driving cases in Alberta, including Calgary and is available 24/7.
