Check your rearview mirrors:
- Often to see how traffic is moving behind you. ✓
- To see if a vehicle is in your blind spot.
- Only when you are slowing down.
Answer: A. Often to see how traffic is moving behind you.
Check your rearview mirrors often to see how traffic behind you is moving.
Why this is the answer
The handbook says that knowing what is behind you helps you avoid rear-end collisions, and it tells you to check traffic behind you often with your rearview mirror, side mirrors, and by turning your head. It lists many times this matters, including lane changes, speed changes, turning, parking, and backing up. That makes frequent mirror checks the right habit, not something limited to one maneuver or to slowing down.
Why the other answers are wrong
- B. To see if a vehicle is in your blind spot. — A rearview mirror is not the tool for seeing a vehicle in your blind spot; the handbook says to check blind spots by turning your head and looking over your shoulder.
- C. Only when you are slowing down. — The handbook lists many reasons to check behind you, including lane changes, turns, parking, and backing up, so limiting mirror checks to slowing down is too narrow.
Remember it
Use the mirror as part of a steady scan, and turn your head when you need to check a blind spot.
Official handbook: California Driver Handbook (DL 600), Section 8: Safe Driving, p. 59