What should a driver always do before changing lanes?

Before changing lanes, a driver must check blind spots to ensure that there are no vehicles or obstacles that might not be visible in the rear-view or side mirrors. Blind spots are areas around the vehicle that cannot be directly seen by the driver and are critical for safe maneuvering. By physically turning their head and checking these areas, the driver can confirm that the lane is clear, reducing the risk of collisions with other vehicles that may not be visible otherwise. This practice enhances overall road safety and is essential for responsible driving.

Other actions like using turn signals, while important for indicating intentions to other drivers, do not address the immediate concern of ensuring the lane change can be executed safely. Sounding the horn or accelerating quickly may distract from the primary concern of monitoring traffic conditions around the vehicle. Therefore, checking blind spots is the most critical action to take before making a lane change.