The UK standards for roundabouts and mini-roundabouts

The modern priority rule for roundabouts was first introduced in the UK during the 1960s and has been in widespread use ever since, gradually being adopted around the world. Roundabouts are recognised as a safe and efficient form of junction, particularly where side road flows are high. Extensive research led to predictive models for both safety and capacity and modern design is based on these relationships. The idea of mini roundabouts was conceived during the 1970s. They are used in the UK in urban areas where a roundabout would be the first choice of junction if space permitted. They usually replace existing priority junctions. Like conventional roundabouts, they are seen as a safe and efficient form of junction. Both capacity and accident predictive relationships have been developed specifically for mini-roundabouts. The new standards for the geometric design of roundabouts and mini-roundabouts were published in 2007 and details are provided in this paper.