Before you change lanes, you should activate your signal and:

Question

Do not rely on other drivers to respond to your signals when you are changing lanes. After activating the proper turn signal, you should verify that there is enough space in the next lane for your entire vehicle to safely merge into the next lane.

Accepted Answer

Check for a space in the next lane.

Answer

Slow down in your traffic lane.

Answer

Sound your horn.

Answer

Flash your lights.