Kiertoliittymä

Kiertoliittymä, commonly known as a roundabout or traffic circle in English, is a type of circular intersection for traffic. Vehicles entering the intersection yield to traffic already in the circle. Traffic flows in one direction around a central island. The primary purpose of a kiertoliittymä is to improve safety and traffic flow compared to traditional intersections with traffic lights or stop signs. By reducing conflict points where vehicles can collide, roundabouts generally lead to fewer severe accidents. They can also help to reduce vehicle idling time, contributing to lower emissions.

The design of a kiertoliittymä typically includes a central island, approach lanes, and exit lanes. Pedestrians and cyclists are usually accommodated with designated crossing points or paths around the circle. The speed of vehicles is naturally reduced as they navigate the curved approaches and enter the roundabout. This slower speed is a key factor in enhancing safety for all road users. Installation of kiertoliittymät has become increasingly common in many countries as a traffic calming measure and an effective alternative to conventional intersections.