kiertoliittymiä

Kiertoliittymiä, commonly known as roundabouts or traffic circles, are a type of circular intersection designed to improve traffic flow and safety at junctions. Instead of a traditional four-way stop or traffic signal, vehicles entering a kiertoliittymä yield to traffic already circulating within the central island. This continuous flow of traffic, when implemented correctly, can reduce delays and the potential for severe collisions.

The design of a kiertoliittymä typically involves a central raised island around which traffic flows in a counter-clockwise direction in countries where traffic drives on the right, and clockwise where traffic drives on the left. Entry and exit lanes are designed to encourage drivers to slow down before entering the roundabout. Pedestrian and cyclist facilities are often integrated into the design, usually with marked crossings located some distance before the roundabout itself.

The primary benefits of kiertoliittymiä include a significant reduction in certain types of accidents, particularly those involving T-bone collisions and head-on impacts, which are common at traditional intersections. By reducing the number of conflict points and the speed of vehicles, kiertoliittymiä generally offer a safer alternative. Furthermore, they can improve traffic capacity by allowing a more continuous movement of vehicles, especially during off-peak hours, although heavy congestion can sometimes lead to delays within the roundabout itself. Their implementation is a common traffic engineering solution worldwide.