Blind Spots: How to Check Them Safely While Driving
Last reviewed: 2026 · Driviology Road Safety Education Team
Quick Answer
Blind spots are the areas around your vehicle that mirrors alone cannot show you, most commonly over each rear shoulder. Always adjust your mirrors correctly and add a quick shoulder check before changing lanes or merging.
Every vehicle has blind spots, and larger vehicles like trucks and buses have even bigger ones. Understanding where they are, and building the habit of checking them every time, is one of the most important defensive-driving skills a new driver can develop.
Where Are a Vehicle’s Blind Spots?
The most common blind spots are the areas just behind and to each side of the vehicle, roughly level with the rear doors, where a side mirror’s view ends and the driver’s peripheral vision does not yet reach. Larger vehicles also have blind spots directly behind and, for trucks, along much of both sides.
Adjusting Your Mirrors
Set your side mirrors wide enough that you see only a sliver of your own vehicle at the inside edge. This reduces overlap with your rear-view mirror and shrinks the blind spot rather than duplicating the same view three times.
The Shoulder Check
Before changing lanes, merging, or pulling away from the curb, glance quickly over your shoulder in the direction you are moving. This single habit catches vehicles, cyclists, and pedestrians that mirrors cannot show. It is also one of the specific actions examiners look for during an Ontario G2 or G road test.
Blind Spots Around Larger Vehicles
Transport trucks and buses have much larger blind spots than passenger cars. As a general rule, if you cannot see the truck driver’s mirror, they likely cannot see you. Avoid lingering directly behind or beside large vehicles, especially near their front corners.