What is the function of a roundabout?

Answer: C — To facilitate the flow of traffic without stop signs or traffic lights

The primary function of a roundabout is to facilitate the flow of traffic without the need for stop signs or traffic lights. Roundabouts are designed to improve traffic efficiency and safety by allowing vehicles to navigate through intersections in a circular pattern. This design minimizes points of conflict between vehicles, as all traffic must yield to vehicles already within the roundabout, reducing potential collisions and enhancing the overall traffic flow. In addition to improving the flow of traffic, roundabouts can also help reduce vehicle speeds, which contributes to safer driving conditions. The circular nature of roundabouts encourages drivers to slow down as they approach and enter the intersection, making them a valuable traffic management tool. Other choices do not align with the primary purpose of roundabouts. For instance, parking, extending cycle lanes, or increasing speed limits are not inherent functions of roundabouts, and these factors do not directly contribute to safety and efficiency as traffic management mechanisms do.