You are driving in the right lane of a multilane highway and want to move into the left lane. You should:
- Look in your rearview mirror for traffic behind you before changing lanes.
- Look over your left shoulder for traffic in your blind spot before changing lanes.
- Look in your side mirror for traffic and turn on your directional signal.
- All of the above. ✓
Answer: D. All of the above.
You should do all of these: check your mirror, look over your left shoulder for traffic in your blind spot, and use your directional signal.
Why this is the answer
The handbook says blind spots sit near the rear corners and cannot be seen in your rear-view mirrors, so before changing lanes you must turn your head to check them. It also says turn signals are required by law when changing lanes. A complete lane change therefore means checking traffic with your mirrors, turning your head to clear the blind spot, and signaling. Doing just one of those things leaves part of the move unchecked.
Why the other answers are wrong
- A. Look in your rearview mirror for traffic behind you before changing lanes. — Looking only in the rearview mirror leaves the blind spot unchecked, and the handbook says those areas are not visible in your mirrors.
- B. Look over your left shoulder for traffic in your blind spot before changing lanes. — Looking over your left shoulder clears the blind spot, but by itself it does not cover traffic behind you or signal your move.
- C. Look in your side mirror for traffic and turn on your directional signal. — Checking a side mirror and signaling does not replace turning your head to check the blind spot, which the handbook specifically requires before a lane change.
Remember it
Mirrors show part of the picture; a head turn covers what they miss before you signal and move.