Behaviours – Drugs and Medication

Police Powers and Screening Tests

Driving while impaired by drugs is a criminal offence. Police officers are trained to administer screening tests to drivers suspected of driving while impaired by drugs.

Physical coordination tests: on the side of the road

Horizontal gaze nystagmus test: eye movement test

The police officer will have you follow a pen with your eyes in order to detect the presence of nystagmus (involuntary, jerky eye movements).

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Test du mouvement des yeux

Eye movement test – video in French only

Transcript :

Walking test: walk-and-turn test

The police officer will ask you to walk on a straight line and turn around.

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Test de la démarche

Walking test – video in French only

Transcript :

Balance test: one-leg stand test

The police officer will also test your ability to perform several tasks simultaneously, such as walking in a straight line or standing on one leg while counting out loud. Under the influence of drugs, it may be difficult to follow all of the police officer's instructions.

Failing these tests are enough to place a driver under arrest.

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Test de l'équilibre

Balance test – video in French only

Transcript :

Drug recognition experts: at the police station

At the police station, specialized police officers administer a series of more extensive tests to determine whether a driver is impaired by drugs, medication or alcohol.

Among other things, they will examine:

  • pulse, body temperature and blood pressure
  • the eyes, in particular the size of the pupils
  • the insides of the nostrils and mouth
  • muscle tone (depending on the drug used, muscles may be either more rigid or more relaxed)
  • the arms and neck, in order to find possible injection sites

You will also be required to provide urine or saliva samples, for example, for toxicological testing.

If the situation so warrants, results will be submitted as evidence to the Directeur des poursuites criminelles et pénales.