What must drivers do when changing lanes according to Title 21?

When changing lanes, drivers must signal and check their blind spots before executing the maneuver. Signaling serves as an important communication tool to inform other road users of the driver’s intentions, thereby enhancing safety on the road. It alerts other drivers and pedestrians that a lane change is about to occur, allowing them to adjust their actions accordingly.

Checking blind spots is equally crucial, as it ensures that the driver is aware of any vehicles that may not be visible in their mirrors. This practice helps prevent accidents by confirming that the lane is clear before making a move. Adhering to these actions reflects responsible driving behavior that promotes road safety for all users.

The other options do not align with safe driving practices. For instance, only signaling if there are cars present could lead to dangerous situations if the driver does not see a vehicle in their blind spot. Changing lanes without any signals fails to communicate intentions, increasing the likelihood of collisions. Lastly, waiting until no cars are in sight might encourage unsafe lane changes in less trafficked conditions and does not promote the standardized practice of signaling, which is essential for maintaining road safety.