Alberta Checkstop Program for Impaired Driving

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The impaired driving law has evolved into an incredibly complex and technical area of criminal law. Many books have been written on the subject and countless judicial decisions have interpreted the dense impaired driving provisions of the Criminal Code.

This article is therefore intended solely as a brief primer on what to expect at a Checkstop. There are immediate and very real consequences to being charged with impaired driving, so your wisest course of action is to seek the assistance of a lawyer experienced in this area.


The Alberta Checkstop Program stops thousands of vehicles each year to check for impaired drivers. The program tends to ramp up around the holiday season, so with Christmas and New Year’s just around the corner, it is important for motorists to know their rights and obligations in the event they get stopped.

To begin, police have an incredibly broad power to stop motor vehicles. A common manifestation of this power is the Checkstop. These often appear as stationary operations where traffic is funneled into a convenient location for sobriety checks. Other times, patrol units engage in roving impaired driving investigations where motorists are randomly pulled over. Whatever form it takes, being pulled over can be an intimidating and often stressful event, even if you have not done anything illegal.


The first thing to remember is to remain calm. If a peace officer directs you to pull over, you must do so. It is an offence to ignore such a direction. When the officer eventually attends at your vehicle, you will typically be asked to produce your license and vehicle documentation. 

You are similarly under a legal obligation to provide this information.  As a main purpose of the Checkstop is to detect impaired drivers, you will also often be asked whether you have recently consumed any alcohol.

While you are under no obligation to answer questions about alcohol consumption, any answer you do give could be used in furtherance of the impaired driving investigation or even other criminal offences.

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What happens at a Checkstop largely depends on what kind of belief the officer is holding in his or her mind. If the officer develops reasonable and probable grounds to believe your ability to drive is impaired by alcohol while interacting with you, then you will be promptly arrested for impaired driving.

If the officer cannot say that your ability to drive is impaired by alcohol, but forms a reasonable suspicion that you have alcohol in your system, then a demand will be made of you to provide a roadside breath sample. You could alternatively be demanded to participate in a so-called field sobriety test (think walking a straight line or balancing on one foot), but that option is rarely exercised. Note that the terms

You could alternatively be demanded to participate in a so-called field sobriety test (think walking a straight line or balancing on one foot), but that option is rarely exercised. Note that the terms reasonable and probable grounds and reasonable suspicion (referenced below) are legal terms with very particular definitions that are beyond the scope of this post.


Let us stop for a moment to address two important questions many motorists have after being detained: Do I have to blow and can I call my lawyer first? With respect to the first question, the short and very simple answer: Yes, you do. You are under a legal obligation to comply with a breath demand. 

The roadside is not the proper forum to be arguing whether the officer has the requisite legal grounds. Should you refuse, you will be charged with refusing to provide a breath sample — an offence which carries with it the exact same penalties as impaired driving.

You will also be charged with refusal should the officer believe you are feigning attempts to provide a usable sample. Faked attempts are seen by police all of the time and are easily recognized. So, if a breath demand is made, you must comply.

With respect to the second question, as it stands, the law is clear that you do not have the right to speak to a lawyer while initially detained during the course of an impaired driving investigation, including driving through a Checkstop. This means that you are not entitled to call your lawyer prior to providing a roadside breath sample.

The suspension of your rights ends, however, when that detention becomes an arrest. At that point, you must immediately be informed of your right to speak with a lawyer and provided a reasonable opportunity to do so. Whether your right to counsel, as guaranteed by section 10(b) of the Charter of Rights and Freedoms, was respected is often an important issue in impaired driving investigations. The law in this area, as in most others, is complex, so it is always best to seek skilled and knowledgeable representation.


Returning to the Checkstop, the actual process of providing a sample of your breath at the roadside involves blowing through a straw into a small handheld instrument called an Approved Screening Device. This device is calibrated to detect whether the concentration of alcohol in the motorist’s blood exceeds certain predetermined limits.

In Alberta, if the Approved Screening Device indicates a reading in excess of 50 milligrams of alcohol in 100 milliliters of blood (“Over .05”), then the motorist’s license will be suspended under the Traffic Safety Act for three days. Longer suspensions would occur if the motorist’s license had previously been suspended for the same reason within the last 10 years.

beer bottle driving

If the Approved Screening Device registers a fail reading, then the motorist will be arrested and charged with impaired driving. In most cases, the motorist will then be required to participate in a second breath test, often at the police station, which more precisely measures the concentration of alcohol in his or her blood.

If that test results in a reading of Over .08, then the motorist will be charged with the additional criminal offence of driving with a blood-alcohol concentration in excess of the legal limit. In Alberta, if you are charged with impaired driving, Over .08 or refusing to provide a breath sample, your license is immediately suspended until your charges are no longer before the court, subject to a successful appeal of the suspension before the Alberta Transportation Safety Board.


This post is not meant to address every step of an impaired driving investigation, but rather just what you might expect at a Checkstop. It does not discuss, for example, what would happen if the officer has reasonable grounds to believe you are intoxicated by a drug rather than by alcohol, or situations where a demand for a sample of your blood is made instead of your breath.

Keep your eyes open for future blog posts on these topics and more. For additional information about the Checkstop program and your rights, give us a call toll-free at 1-877-277-4766 or email us at

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