Alertness
You want to move into the next lane on a dual carriageway. What must you do before you change lanes?
- Signal only, since other drivers will see the indicator
- Check your mirrors and look over your shoulder for the blind spotCorrect
- Sound your horn to clear the lane
- Speed up so you can move across quickly
Why?
Mirrors don't show everything, so before changing lanes you need a final check over your shoulder for the blind spot as well as your mirrors, then signal in good time. Rule 133 of The Highway Code says you should judge whether it's safe to change lanes this way, never by speed or the horn alone.
Highway Code rule 133