Rules & regulations

What is a Field Sobriety Test?

Officers who are drug recognition experts can check you for impairment in a roadside test if they suspect you are driving under the influence of drugs or alcohol or both.

Toronto’s Constable Clinton Stibbe says officers decide whether to conduct a field test on a case-by-case basis - and you could be taken straight to the police station if an officer thinks that is the best course.

Here’s the most usual scenarios for a field sobriety test:

Preliminary evaluation

An officer will check your pulse and inspect your pupils to see if they’re the same size. If you’re under suspicion for impaired driving, a series of tests may follow.

Eye tests

  1. The horizontal/vertical gaze nystagmus tests (try saying that drunk):

    An officer could ask you to follow a pen or similar object closely with your eyes, and check if you twitch involuntarily, which usually occurs when a person is drunk.

    TRUE STORY: This one guy thought the field sobriety tests were going to be a breeze. He failed miserably.
  2. The lack-of-convergence test:

    Officers will literally test you till you’re cross eyed, which you’ll be unable to do if you’re drunk. An an officer will ask you to follow an object with your eyes, while bringing it closer and closer to your nose - basically until you’re cross eyed.

Coordination tests

  1. The walk-and-turn test:

    You may be asked to walk along a straight line, putting your heel directly in front of your toe, and then turn around and do it again.

  2. The one-leg stand test:

    Exactly as it sounds: you’ll have to stand on one leg and count out loud.

  3. The Romberg balance test:

    For this test, you’ll be asked to stand with your feet together, tilt your head back, close your eyes and count 30 seconds. The officer will watch your balance, movement (whether you sway or twitch) as well as your judgement of time.

  4. The finger-to-nose test:

    You’ll be asked to tilt your head back and touch the tip of your index finger to the tip of your nose - with your eyes closed.

What happens if I fail the Field Sobriety Test?

If a police officer suspects that you're driving impaired under the influence of drugs (illegal or prescription) because of how you performed in the test, they can decide to arrest you.

You would then be asked to give a urine, blood or saliva sample at a police station. This is checked for drugs and can be used to secure a drug driving conviction - but refusal to give a sample is also an offence and you can still be convicted of drug driving.

Scary? Yup. So be warned!


Farida started writing for ingenie in 2015. She got her Ontario licence in 2014 and her first car was a manual 2003 VW Jetta GLS 1.8T. Follow her on Twitter.