What is the purpose of a traffic circle?

The purpose of a traffic circle is primarily to allow multiple directions of traffic to flow smoothly. Traffic circles are designed to manage the convergence of various roads and can effectively improve the movement of vehicles and pedestrians at busy intersections. By allowing vehicles to travel in a continuous, circular motion around a central island, traffic circles minimize stop-and-go scenarios that can cause congestion and delays. This design not only enhances traffic flow but also reduces the likelihood of severe accidents, as vehicles enter the circle at lower speeds and yield to others already in the circle.

In contrast, the other options don't accurately reflect the main function of a traffic circle. While they may influence aspects of traffic management in certain situations, they do not align with the fundamental purpose of a traffic circle. For example, while it may reduce speed at points of entry and exit, the primary goal remains to facilitate smooth traffic movement rather than merely lowering speed or adding stop signs. Additionally, creating more parking space is not a design objective of traffic circles.