Design Philosophy of a Concrete Bone Roundabout (CBR)

The Netherlands has made a clear decision to increase traffic mobility by reducing the use of traffic lights wherever possible. If traffic lights are not to be used, crossings need to be changed. The easiest solution is to change crossings into roundabouts and this solution (depending of the volume of traffic) is also the best one in terms of sustainability, traffic safety and mobility. Where the volume of heavy traffic is quite high, asphalt roundabouts are very prone to rutting. This will push rigid pavements into the limelight, as has happened in the case of a twin roundabout connected to the access ramps of the new A73 highway in the south of the Netherlands (in the Province of Limburg). A bird’s-eye view of the twin roundabout reveals a bone-shaped design. This paper presents the design philosophy, including the slab design and detailing of joints.