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Blind spots: how do you check them, and when?

Mirrors are never enough: you have to turn your head.

What is a blind spot?

Even when properly adjusted, the inside mirror and side mirrors show only part of what surrounds the vehicle. Areas at the front, on the sides and at the back remain invisible: these are blind spots. Adjusting your mirrors reduces them but never eliminates them; only a direct look into the blind spot gives a complete view (Conduire un véhicule de promenade, the SAAQ driving manual, ch. 2, “Les angles morts”).

The windshield pillars also create blind spots big enough to hide a pedestrian, a cyclist, a motorcycle or even a car, especially when approaching intersections in town. The manual advises shifting slightly in your seat to look around them.

How to do the check

• Quickly turn your head toward the side you want to move to and look over your shoulder, without moving your body.
• Keep the same speed during the glance: no braking, no accelerating.
• Make it very quick, so you don’t lose track of what is happening ahead.
• The goal: make sure no vehicle, cyclist or pedestrian is in the blind spot.

Source: Conduire un véhicule de promenade, ch. 2, “Les angles morts”.

When should you check?

Every time you are about to change your path or there is a risk of collision, in particular before you:

• merge into traffic or leave it;
• change lanes;
• turn at an intersection;
• reverse;
• pull out of a parking spot.

Mirrors, on the other hand, are checked often: the manual suggests every 10 to 12 seconds, even on a straight road, and before slowing down or stopping. It also warns about the right-hand mirror, which makes vehicles look farther away than they are.

The order of steps to change lanes

1. Check your mirrors.
2. Check the blind spot on the side you are moving to.
3. Turn on your signal.
4. Check the mirrors again, then the blind spot again, while holding your path.
5. Change lanes gradually and adapt your speed to the new lane.
6. Turn off your signal.

Source: Conduire un véhicule de promenade, ch. 3, “Changer de voie”. The Code de la sécurité routière (Quebec’s Highway Safety Code) requires you to signal with your turn signals and make sure the manoeuvre can be done safely (s. 372), continuously and over a sufficient distance (s. 375).

Trucks’ blind spots

A heavy vehicle has blind spots at the front, the rear and on the sides. The Guide de la route gives a simple rule of thumb: if you cannot see one of the truck’s side mirrors, you are following too closely. Also avoid driving alongside a truck or taking too long to pass it, and don’t cut back in front of it too quickly (ch. 4, “Le partage de la route avec les véhicules lourds” and “Les angles morts des véhicules lourds”).

In general, avoid staying in another road user’s blind spot for long, so you are not caught off guard by a sudden move on their part (Conduire un véhicule de promenade, ch. 2).

Key points for the test

• Mirrors well adjusted: blind spots still exist.
• Check = quick glance over the shoulder, steady speed.
• Before any change of path: lane, turn, merge, reverse, leaving a parking spot.
• Truck: can’t see its mirror = too close.

See also

• Following distance and stopping distance
• Distance for passing a cyclist
• Yellow lines and passing

Official sources

• Code de la sécurité routière (Highway Safety Code, CQLR c. C-24.2), ss. 372 and 375
• SAAQ, Conduire un véhicule de promenade (2022 ed., French), ch. 2, “En arrière” and “Les angles morts”; ch. 3, “Changer de voie”
• SAAQ, Guide de la route (4th ed., 2024, French), ch. 4, “Le partage de la route avec les véhicules lourds” and “Les angles morts des véhicules lourds”

General information page, current as of 2026-10-28. If in doubt, the official text prevails. Rules can change: check saaq.gouv.qc.ca and legisquebec.gouv.qc.ca.