Sobriety tests and police questioning
Upon pulling you over, police may demand you perform physical coordination tests at the roadside. Before making the demand, police do not have to tell you that you have a right to speak to a lawyer. You must perform the tests. Non-compliance carries the same penalties as drinking and driving. Police can use the test results only to determine if there are grounds to arrest you for impaired driving and for a demand either for a breath sample or for the performance at a police station of additional tests to determine if you are impaired by a drug. The Crown cannot use the results of the physical tests to establish impairment at your trial.
Upon pulling you over and before arresting you, police also can ask you questions about how much you have had to drink. Police can ask these questions before telling you about your right to a lawyer. You do not have to answer such questions. But if you do, police can use your responses to determine if you have alcohol in your body. If police believe that you do, they may require you to provide a breath sample into a roadside screening device. However, the Crown cannot use your responses (or a fail result on the device) to prove guilt.
At the station
The police officer who operates the breath testing device may ask you to perform physical coordination tests such as walking a straight line (“heel-to-toe test”) and touching your finger to your nose. Do not participate in such tests. Some are difficult to perform sober. (Note: Such tests are not to be confused with mandatory tests to determine if you are impaired by a drug.) You may be nervous and underestimate your impairment. You are not required by law to do the tests. In addition, the police officer who operates the breath device will ask you questions. Do not answer. Many of the questions (e.g., were you driving a motor vehicle tonight, what were you drinking, how much and when) are designed to elicit responses for use against you at trial.
“How impaired, on a scale of 1-10?”
Police might ask: “How impaired are you on a scale of one to ten, one being sober and ten being the most intoxicated you’ve ever been?” Any answer greater than one may suffice to convict you of impaired driving as the Supreme Court of Canada has held that the offence is made out where your ability to operate a motor is even slightly impaired.