What is the primary purpose of a roundabout?

The primary purpose of a roundabout is to improve traffic flow and reduce the severity of collisions at intersections. Roundabouts are designed as circular intersections that facilitate continuous traffic movement, allowing vehicles to navigate smoothly without the need for traffic signals or stop signs. They help to lower vehicle speeds, which can significantly decrease the likelihood of high-speed collisions and serious accidents. By channeling traffic into a single direction around a central island, roundabouts prevent head-on and T-bone crashes, making them safer than traditional intersections.

In contrast, other options focus on aspects that are not the main intent of roundabouts. While pedestrian crossings can be part of a roundabout's design, the primary goal remains traffic management and safety. Additionally, roundabouts do not increase speed limits; instead, they encourage reduced speeds to enhance safety and efficiency. Parking space availability is not a function of roundabouts, as their layout primarily addresses vehicle flow rather than parking logistics. Therefore, the choice that identifies improved traffic movement and safety as the main goal accurately reflects the designed purpose of roundabouts.