What should you do before changing lanes?

Before changing lanes, it is essential to check your mirrors and blind spots to ensure that the lane is clear and safe for you to move into. This step is crucial for identifying any vehicles or obstacles that may not be visible in your mirrors but could be present in your blind spots. This action helps prevent accidents and ensures that you do not endanger yourself or other road users.

Activating your headlights may be important in certain conditions, such as low visibility, but it does not specifically relate to the action of changing lanes. Changing lanes quickly can increase the risk of collisions, as it does not allow sufficient time for you to assess your surroundings. Waiting for other cars to signal does not guarantee safety, as the responsibility for changing lanes safely ultimately rests with you as the driver. Thus, checking mirrors and blind spots is the only option that directly contributes to making a safe lane change.