What should you always do before changing lanes?

Before changing lanes, it is essential to follow a sequence of safety checks to ensure the maneuver is done safely and courteously. This process includes checking your rearview mirror, performing a head check, and signaling your intention to other drivers.

Checking your rearview mirror allows you to see what is behind you and any vehicles that may be closing in on your space. This step is crucial to understand your current position in relation to traffic.

Performing a head check supplements the rearview mirror assessment by allowing you to visually confirm that the lane you wish to move into is clear. This checks the blind spots that may not be visible in mirrors.

Signaling your intention is a critical part of safe driving as it communicates to other road users your intention to change lanes. This provides them with the necessary information to respond appropriately, reducing the likelihood of accidents.

By combining these actions—checking mirrors, doing a head check, and signaling—you create a comprehensive approach to safely changing lanes, which is why doing all of these is the correct answer.