What is required before changing lanes or making a U-turn?

To ensure safety when changing lanes or making a U-turn, it is essential to check your surroundings using the rearview mirror and signal your intentions to other drivers. The rearview mirror provides a view of traffic behind you, while signaling alerts other motorists of your planned maneuver. This dual-action promotes safer driving by reducing the likelihood of surprises that could lead to accidents. It is a critical part of defensive driving, emphasizing the importance of being aware of your environment and communicating your actions effectively to others on the road.

The other options lack a full understanding of safe driving practices. Simply signaling or relying on only one mirror does not provide comprehensive awareness of surrounding traffic. Moreover, changing lanes without signaling contradicts safe driving protocols and could confuse other drivers, increasing the risk of collisions. Thus, both checking your mirrors and signaling are necessary for a responsible change of lanes or U-turn.