Magic Roundabout (Swindon) be reconfigured while the layout was fine tuned. A police officer was stationed at each mini roundabout during this pilot phase to oversee how drivers coped with the unique arrangement. The roundabout is built over a section of the old Wilts and Berks Canal – Swindon wharf. A narrow, stone bridge built c. 1810, which is a grade II listed building, carried the old Saxon way known as Drove Road over the canal half a mile east of the town centre. Its site became covered by Drove Roundabout, which was later redeveloped as the Magic Roundabout. A wharf occupied one
Roundabout Devices. Roundabouts are generally not appropriate for placement on motorway or freeway mainlines because the purpose of such facilities is to provide for uninterrupted traffic flow. However, roundabouts are often used for the junction between the slip roads (ramps in North America) and the intersecting road. A single roundabout, grade separated from the mainlines, may be used to create a roundabout interchange. This type of junction is common in the UK and Ireland. Alternatively, separate roundabouts also may be used at the slip road intersections of a diamond interchange to create what often is referred to as a "dumbbell interchange",