What is the function of a roundabout?

Answer: B — To facilitate continuous movement of traffic

The function of a roundabout is primarily to facilitate the continuous movement of traffic. Roundabouts are designed to improve flow at intersections by allowing vehicles to enter and exit without stopping, which reduces congestion and minimizes the likelihood of accidents. Vehicles traveling in a circular pattern around the central island only yield to traffic already in the roundabout, thus maintaining a steady flow. This design also encourages lower speeds, enhancing safety for all road users, including pedestrians and cyclists. In contrast, options related to providing parking space or acting as a traffic light are not pertinent to the function of a roundabout, as these structures serve different purposes altogether. Roundabouts aim to keep traffic moving rather than controlling it with stops or dedicated parking areas.