Traffic safety effects on roundabouts: a review with emphasis on bicyclist's safety

Abstract

Roundabouts almost exist as long as cars do. Roundabouts in their actual design originate from large traffic circles as they were built in France in the beginning of the 19th Century. In 1903 the Paris architect Eugène Hénard developed the principle of an intersection where all the road users (at that time mainly horses and coaches) had to make a circulatory movement around an obstacle in the middle. Later on, especially in Great Britain much experience was acquired with roundabouts. (Brown, 1995; Certu, 2000; Thai & Balmefrezol, 2000). Give-way-priority to the circulatory traffic on roundabouts was generalised in Great Britain in 1966. Roundabouts have become common in Europe during the 80’s and the 90’s of the twentieth century. In the United States the use of roundabouts is rather limited (Persaud et al., 2001), although it is increasing. The aim of this paper is to give an overview of safety effects of roundabouts. Emphasis is put on effects for bicyclists.