What should you do if you approach a roundabout?

When approaching a roundabout, the appropriate action is to yield to traffic that is already in the roundabout. This is essential because vehicles within the roundabout have the right of way. By yielding, you allow the flow of traffic to continue smoothly, preventing potential collisions and traffic backups.

Roundabouts are designed to enhance traffic efficiency and reduce accidents. They encourage a continuous movement of vehicles without the need for traffic lights, but this only works if drivers follow the yielding rules.

Other options, such as entering immediately or stopping completely, would disrupt the flow of traffic and could lead to dangerous situations. Signaling left is not a requirement simply for entering a roundabout but rather is used to indicate your intention to exit. Thus, yielding to existing traffic is the correct and safest practice in this scenario.