Free independent learning reference with original examples. Not official exam questions or personalized legal advice. Follow current provincial rules, signs and authorized directions.
Practise lane changes →Mirrors show part of the scene
An empty mirror is useful information, but it does not prove that the whole adjacent lane is empty. A motorcycle or bicycle can be alongside the car outside the reflected view. Adjust the mirrors before setting off, then keep updating your picture of surrounding traffic.
The question to answer is specific: is the space I am about to enter available now? A shoulder check looks toward that space. It is a brief check within continued observation of the road ahead, rather than a prolonged look behind.
Source: SGI — Blind spots ↗Check the lane you intend to enter
SGI’s lane-change procedure combines planning, signalling, mirrors and a shoulder check before steering. Look left for a leftward move and right for a rightward move. A signal communicates your plan; it does not require someone already alongside to clear the lane.
If traffic prevents the move, keep your current lane and reassess. An earlier clear check can become stale while you wait. For movement across more than one lane, SGI specifies a shoulder check for each lane change.
Source: SGI — Changing lanes ↗Apply the check to changing traffic
Original worked cases
A car’s left mirror appears empty, but a motorcycle is beside the rear door. A left shoulder check reveals the conflict. The driver stays in the existing lane instead of beginning the move.
A driver checked right, then waited behind slow traffic. Before moving several seconds later, the driver checks again. The original observation does not reserve the gap.
A driver plans to reach a lane two lanes away. Checking only before the first move leaves the second adjacent space unexamined. Each lane change needs its own check.
Practise identifying the missing observation
When reviewing a missed question, separate looking from signalling and steering. Ask which observation would reveal the hidden road user. Do not select an answer merely because it mentions a mirror if the scenario concerns an area the mirror cannot show.
The free lane-change questions below let you review explanations without a subscription. These original cases teach observation decisions; they do not replace supervised driving practice or the complete SGI handbook.
Source: SGI — Changing lanes ↗