Toronto Criminal Lawyer

Being pulled over by police is stressful for anyone, but the situation becomes especially tense when an officer begins roadside testing for impairment. Whether at a RIDE checkpoint during a holiday weekend or during a routine traffic stop, understanding what police can lawfully require of you — and what falls outside the scope of their authority — is important for protecting your rights.

Ontario's roadside testing framework changed significantly with the introduction of mandatory alcohol screening in December 2018. These changes expanded police powers, but they did not eliminate the constitutional protections that every driver retains. This article explains the current legal landscape for roadside testing in Ontario.

Mandatory Alcohol Screening: The Current Law

Since December 18, 2018, police officers in Canada have had the authority to demand a breath sample from any driver they lawfully stop — without needing to suspect that the driver has been drinking. This power comes from amendments to the Criminal Code under former Bill C-46, now reflected in section 320.27(2).

Before these amendments, officers needed "reasonable suspicion" that a driver had alcohol in their body before they could demand a roadside breath test using an approved screening device (ASD). That threshold has been removed. Today, if an officer has a functioning ASD available, they can demand a sample from any driver during any lawful stop.

This means that during a RIDE (Reduce Impaired Driving Everywhere) checkpoint, or even a stop for a burned-out tail light, the officer can ask you to blow into an ASD. A "fail" result on the ASD provides the officer with grounds to demand a more comprehensive breath test at the station using an approved instrument, typically the Intoxilyzer.

The constitutionality of mandatory alcohol screening has been challenged in courts across Canada. While the Supreme Court of Canada has not yet rendered a definitive ruling on section 320.27(2) specifically, lower courts have generally upheld the provision, relying on the reasoning in earlier decisions that roadside breath demands constitute a reasonable limit on Charter rights given the serious public safety concerns associated with impaired driving.

What Officers Can Do at the Roadside

Police officers conducting roadside testing have several tools at their disposal. Understanding what falls within their lawful authority helps set realistic expectations during a stop:

• Demand an ASD breath sample — Under mandatory alcohol screening, no suspicion of drinking is required. The officer must have an approved screening device available and the demand must be made during a lawful stop.
• Conduct a Standardized Field Sobriety Test (SFST) — If an officer has reasonable suspicion that a driver's ability is impaired by alcohol or a drug, they can demand that the driver perform physical coordination tests at the roadside. These include the horizontal gaze nystagmus test, the walk-and-turn test, and the one-leg stand test.
• Demand an oral fluid sample — Under section 320.27(1)(a.1), if an officer reasonably suspects a driver has drugs in their body, they can demand an oral fluid sample using approved drug screening equipment.
• Demand a Drug Recognition Expert (DRE) evaluation — If there are reasonable grounds to believe impairment by drug, the officer can require a more detailed evaluation at the station conducted by a trained DRE officer.
• Observe and note indicators of impairment — Officers will note the smell of alcohol, bloodshot eyes, slurred speech, fumbling with documents, and other observable signs. These observations can form the basis for further demands.

What Officers Cannot Do

Despite their broad powers, police officers are still bound by constitutional limits and procedural requirements. There are several things officers cannot lawfully do during a roadside stop:

• Conduct a stop without lawful authority — A traffic stop must be lawful in the first place. Officers can stop vehicles under the Highway Traffic Act to check licences, insurance, and vehicle fitness, or under the Criminal Code if they have grounds. A stop motivated by racial profiling or other improper purposes can be challenged.
• Delay unreasonably — Roadside testing must be conducted promptly. Courts have found that excessive delays between a stop and a breath demand can violate the driver's rights under sections 9 and 10 of the Canadian Charter of Rights and Freedoms.
• Deny the right to counsel at the station — While there is no right to speak with a lawyer before providing a roadside ASD sample, once an officer makes a demand for a breath or blood sample at the station (using an approved instrument under section 320.28), the driver must be informed of their right to retain and instruct counsel without delay.
• Use physical force without justification — Officers cannot physically force you to blow into an ASD. However, refusal or failure to comply with a lawful demand is itself a criminal offence under section 320.15 of the Criminal Code.
• Search your vehicle without grounds — A roadside breath demand does not give the officer authority to search your vehicle. A vehicle search requires either consent, a warrant, or grounds that fall within a recognized common-law or statutory power.

What Happens If You Refuse a Roadside Test

Refusing to comply with a lawful demand for a roadside breath sample is a criminal offence. Under section 320.15 of the Criminal Code, refusal or failure to comply carries penalties that mirror those for impaired driving. For a first offence, this includes a mandatory minimum fine of $2,000 — the same minimum as for a first-offence impaired driving conviction with a blood alcohol concentration at or over 80 milligrams of alcohol in 100 millilitres of blood.

The penalties for refusal were deliberately set at this level to remove any incentive to refuse testing. In practical terms, refusing a breath demand often results in worse consequences than complying, because the Crown does not need to prove your actual blood alcohol concentration — only that you refused a lawful demand.

There are limited defences to a refusal charge. A "reasonable excuse" may apply in narrow circumstances — for example, if a medical condition genuinely prevents you from providing a sufficient sample. However, courts interpret this defence strictly. For more detail on the consequences of refusing, see our page on what happens if you refuse a breathalyzer.

RIDE Programs and Your Rights

RIDE checkpoints are a common feature of Ontario policing, particularly during the holiday season and summer long weekends. The legality of these checkpoints was established by the Supreme Court of Canada in R. v. Ladouceur (1990) and R. v. Hufsky (1988), which held that random vehicle stops for the purpose of checking sobriety, licences, and vehicle fitness are a reasonable limit on the right against arbitrary detention under section 9 of the Charter.

At a RIDE checkpoint, officers will typically approach your vehicle, identify themselves, and ask a brief series of questions. They may ask where you are coming from, whether you have consumed any alcohol, and may observe your demeanour. With mandatory alcohol screening now in place, they may also demand a breath sample using an ASD regardless of whether they observe any signs of impairment.

You are not required to answer questions about where you have been or whether you have been drinking. However, you are required to comply with lawful demands for identification, your driver's licence, vehicle registration, and proof of insurance under the Highway Traffic Act. You must also comply with a lawful demand for a breath sample.

Challenging Roadside Testing in Court

If you have been charged with impaired driving or refusal following a roadside stop, the circumstances of the stop and testing process are often central to the defence. Common grounds for challenging roadside testing include:

• Unlawful stop — If the initial traffic stop was not conducted for a lawful purpose, any evidence obtained as a result may be excluded under section 24(2) of the Charter.
• ASD malfunction or improper calibration — The approved screening device must be functioning properly and operated according to established procedures. Defence counsel will review maintenance and calibration records.
• Unreasonable delay — Significant delays in administering the ASD or in transporting the driver to the station can form the basis of a Charter challenge.
• Failure to inform of right to counsel — At the station, any failure to promptly inform the accused of their right to a lawyer can lead to exclusion of breath test results.

Each case depends on its specific facts. The admissibility of roadside test results is frequently litigated in Ontario courts, and the outcome often turns on the precise sequence of events during the stop. If you are facing impaired driving charges following a roadside stop, obtaining experienced legal representation early in the process can make a meaningful difference.

For a broader overview of the criminal process following an arrest, see our guide on what happens after an arrest in Ontario. If you have questions about a specific situation, contact our office to arrange a confidential consultation.