What must you do if you want to change lanes?

To change lanes safely, the correct approach involves signaling your intention, checking your mirrors, and looking for blind spots. This ensures you communicate your plans to other drivers while also confirming that the lane you intend to enter is clear.

Signaling informs other motorists of your next move, which is crucial for maintaining road safety. Checking mirrors allows you to see vehicles that may be alongside you and assess traffic conditions. Looking for blind spots is essential because mirrors do not cover all areas around your vehicle. This three-step process helps prevent accidents caused by merging into occupied lanes or failing to account for drivers who may not be visible in your mirrors.

Using just a turn signal or only checking mirrors does not provide a complete picture of your surroundings. Speeding up aggressively is dangerous and increases the risk of collisions, as it does not allow for a safe entry into the new lane. Therefore, the comprehensive approach described in the correct answer is vital for a safe lane change.