Operation while impaired (alcohol) is one of the most common and serious driving-related crimes in Canada. Often referred to as “impaired driving” or “DUI,” this offence covers both driving while your ability is actually affected by alcohol and driving with a blood alcohol concentration (BAC) at or above the legal limit. Under Uniform Crime Reporting (UCR) Code 9230 and section 320.14(1)(a) and (b) of the Criminal Code, operation impaired alcohol is a hybrid offence, meaning it can proceed either summarily or by indictment depending on the circumstances and the Crown’s election.
The Legal Definition
The offence of operation while impaired (alcohol) is committed when a person:
(a) operates a conveyance while the person’s ability to operate it is impaired to any degree by alcohol; or
(b) operates a conveyance and has, within two hours after ceasing to operate it, a blood alcohol concentration equal to or exceeding 80 mg of alcohol in 100 mL of blood.
This definition comes from section 320.14(1)(a) and (b) of the Criminal Code. In plain English, the law creates two main ways a person can commit the offence of operation while impaired (alcohol):
First, under paragraph (a), your actual ability to drive or operate a “conveyance” (which includes cars, trucks, motorcycles, boats, and some other motorized vehicles) must be impaired by alcohol “to any degree.” This means the Crown does not need to prove you were falling down drunk. Any level of alcohol-related impairment in judgment, coordination, reaction time, or attention can meet the threshold if it affects your ability to operate safely.
Second, under paragraph (b), the law creates a so‑called “per se” offence. Even if there is no obvious outward impairment, you commit the offence if, within two hours of driving, your BAC is at or above 80 mg of alcohol in 100 mL of blood (0.08%). This two‑hour window is designed to prevent people from avoiding liability by delaying or manipulating breath or blood testing. As long as the reading within that two-hour period meets or exceeds the legal limit, the elements of this version of the offence can be satisfied.
Penalties & Sentencing Framework
- Offence classification: Hybrid (can be prosecuted summarily or by indictment)
- Mandatory minimum penalty (first conviction): $1,000 fine
- Maximum penalty on summary conviction: Fine and/or imprisonment up to 6 months
- Maximum penalty on indictment: Fine and/or imprisonment up to 10 years
- If offence causes bodily harm: Up to 14 years’ imprisonment
- If offence causes death: Up to life imprisonment
Because operation impaired alcohol is a hybrid offence, the Crown prosecutor chooses whether to proceed by summary conviction (generally used for less serious cases with lower moral blameworthiness and limited consequences) or by indictment (reserved for more serious or aggravated cases). This election significantly affects the range of available penalties, the procedure, and potential long-term consequences.
For a first conviction, Parliament has imposed a mandatory minimum fine of $1,000. The court cannot go below this minimum even in sympathetic circumstances. However, the judge can increase the fine, impose probation, and, depending on provincial and federal regimes, order driving prohibitions. For repeat offenders, mandatory minimums escalate and can include mandatory jail terms, although those details go beyond the basic framework summarized here.
On a summary conviction, the maximum sentence is a fine and/or up to 6 months’ imprisonment. On an indictable conviction, the maximum rises substantially to 10 years’ imprisonment, reflecting Parliament’s view of impaired driving as a serious threat to public safety. Where the impaired operation causes bodily harm, the maximum can reach 14 years, and where it causes death, the maximum is life imprisonment. In those more serious outcomes, impaired operation is treated as a violent, life‑altering offence, not just a “traffic” matter.
Common Defenses
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Post-Consumption Defence
The post-consumption defence directly targets the “per se” version of the offence under section 320.14(1)(b). A person may argue that while their BAC was at or above 80 mg/100 mL within two hours of driving, this was only because they consumed alcohol after they stopped operating the vehicle. To succeed, the accused must show (often with expert evidence or credible testimony) that they consumed alcohol post‑driving and had no reasonable expectation they would need to provide a breath or blood sample. Their pattern and timing of drinking must be consistent with having been below 0.08% at the actual time of driving. This defence does not usually help with the paragraph (a) “impairment” charge if there is evidence that the driver’s ability was actually affected while driving, but it can defeat the over‑80 component where the only issue is the BAC at the testing time.
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Charter Rights Violation (Sections 8 and 10)
The Canadian Charter of Rights and Freedoms often plays a decisive role in impaired driving cases. Two provisions are especially important: section 8 (protection against unreasonable search and seizure) and section 10 (rights on arrest or detention, including the right to counsel). Breath and blood demands, roadside screening, and detentions for suspected impaired driving all engage these rights. If police obtain breath samples, statements, or other evidence by breaching these rights—for example, by failing to promptly inform the driver of the right to counsel, not allowing them a reasonable opportunity to contact a lawyer, or demanding breath samples without the reasonable grounds required by law—the defence can ask the court to exclude the evidence under section 24(2) of the Charter. Since BAC readings are often central to proving an offence under section 320.14, exclusion of this evidence can lead to an acquittal.
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Procedural Non-Compliance (Sections 320.27 and 320.28)
Sections 320.27 and 320.28 of the Criminal Code set out detailed rules for roadside screening, evidentiary breath testing, and related procedures. Police must follow strict steps when making a demand, using an approved screening device (ASD), transporting a person for evidentiary breath tests, and operating approved instruments. Procedural non-compliance can include failing to properly inform the accused of the demand, using an ASD or breath instrument that is not correctly calibrated or maintained, delaying tests beyond what is reasonably necessary, or otherwise disregarding the statutory requirements. Such failures can undermine the reliability or admissibility of the BAC results. Defence counsel may argue that these procedural errors render the evidence unreliable or that they amount to Charter breaches, again seeking exclusion of the key breath or blood evidence. If the prosecution’s main proof of impairment or BAC is excluded or discredited, reasonable doubt may result and the accused can be acquitted.
Real-World Example
Imagine someone leaving a party feeling “a bit buzzed” but still believing they are capable of driving. They drive home and, on the way, a police officer notices the vehicle weaving slightly within the lane and braking late at a yellow light. The officer pulls the driver over to check sobriety. The officer observes an odour of alcohol, slightly slurred speech, and red, glassy eyes, and decides to make a roadside screening demand under section 320.27. The driver blows into an approved screening device and fails. They are then taken to a police station, where an approved instrument shows a BAC above 80 mg/100 mL within an hour of driving. In this scenario, the driver could be charged with both impaired operation (for the observable signs of impairment under 320.14(1)(a)) and the “over 80” per se offence (under 320.14(1)(b)). The court would examine whether the officer had the proper grounds to stop, screen, and test the driver, whether all procedures and Charter rights were properly respected, and whether the evidence proves beyond a reasonable doubt that the driver’s ability was impaired and/or that the BAC exceeded the legal limit within two hours of driving.
Record Suspensions (Pardons)
Because operation impaired alcohol is a hybrid offence, the waiting period for a record suspension (pardon) depends on how the Crown proceeds and how the conviction is recorded. For a summary conviction, a person generally becomes eligible to apply for a record suspension 5 years after completing all aspects of their sentence, including any fine payments, probation, and driving prohibitions. For an indictable conviction, the waiting period is longer: eligibility usually arises 10 years after sentence completion. A record suspension does not erase the conviction but can separate it from publicly visible criminal record checks in many contexts, significantly improving employment and travel prospects. However, impaired driving convictions, especially where bodily harm or death occurred, may receive closer scrutiny by the Parole Board of Canada, and the existence of minimum penalties and aggravating factors can influence the Board’s assessment of risk and rehabilitation.
Related Violations
- Over 80 mg Operation
- Refusal to Provide a Breath Sample
- Driving While Prohibited