What must be done before making a lane change?

Before making a lane change, it is crucial to check mirrors and blind spots, and signal your intent. This practice ensures that the driver is fully aware of their surroundings, including any vehicles or obstacles that may be in the blind spots, which are areas not visible through standard mirrors.

By checking the mirrors, a driver observes the traffic conditions behind and beside them. However, mirrors do not cover every angle, which is why checking blind spots—turning your head to look over your shoulder—is essential for safety. Signaling your intent is equally important as it communicates to other drivers what you plan to do, helping to prevent misunderstandings or collisions. Collectively, these actions contribute to safer lane changes and help maintain a smooth flow of traffic.

Each of the other options fails to encompass the necessary safety measures. For instance, only checking the rearview mirror would ignore blind spots, and signaling without checking could lead to dangerous situations if another vehicle is present in the blind spot. Accelerating before changing lanes can also lead to abrupt maneuvers that compromise safety. Thus, checking mirrors and blind spots while signaling provides a comprehensive approach to safely changing lanes.