When performing a lane change, you should stay within _______ of the posted speed limit.
- 15 km/h
- 20 km/h
- 10 km/h ✓
- 5 km/h
Answer: C. 10 km/h
When you change lanes, you should stay within 10 km/h of the posted speed limit, as long as conditions allow and you do not go over the limit.
Why this is the answer
The handbook's lane change section says to operate within 10 km/h of the posted speed limit if conditions permit, without exceeding the posted limit. Keeping your speed close to the limit while you signal, check mirrors and move over keeps the traffic pattern around you predictable. Going much slower or faster than the surrounding traffic makes the move harder for others to read, and the handbook warns that hesitating lets traffic patterns change during the lane change.
Why the other answers are wrong
- A. 15 km/h — 15 km/h is wider than the margin the handbook gives, and it would let your speed drift further from the traffic around you during the move.
- B. 20 km/h — 20 km/h is twice the margin the handbook states, so it does not match the rule for lane changes.
- D. 5 km/h — 5 km/h is tighter than the handbook requires; the stated margin is 10 km/h, not half of it.
Remember it
The lane change margin matches a round number: think of a 10 km/h band around the posted limit, and never above it.
Official handbook: Official MTO Truck Handbook, Lane changes