Roundabouts have become a commonly used solution for intersections in the Netherlands and have a considerable impact on road safety. It is recommended that a separate cycle track is preferable for application on roundabouts with both a capacity of circa 8,000 motor vehicles per 24 hour period and a significant volume of bicycle traffic. It may be contended that at least roundabouts with separately lying cycle tracks whereupon cyclists are not given right of way are safe. In principle, it is not advisable to construct roundabouts with a cycle lane. In principle, roundabouts with separate cycle tracks are preferable for situations outside built-up areas. It is recommended that cyclists are not given right of way. Five design elements have proven to be of great significance for the effective functioning of roundabouts. These relate to: (1) the internal radius; (2) the external radius; (3) the carriageway width; (4) the connecting bends of approach and exit roads; and (5) the application of central guard rails. On specifying dimensions for a roundabout, explicit account must be taken of the ease of passage for buses and heavy goods vehicles.
Abstract