Magic Roundabout (Hemel Hempstead) viaduct. The BP building was found to be unstable due to defective reinforced concrete and the exit had to be closed. The building was demolished but the original route was not restored, although a newer side exit from the roundabout replaced the junction with Marlowes off a side road. Magic Roundabout (Hemel Hempstead) The "Magic Roundabout" in Hemel Hempstead, Hertfordshire, England, is the familiar name given to the Plough roundabout. The familiar name comes from the children's television programme, and is also used for a similar junction in Swindon and the M40 junction in Denham. The official name relates to
Roundabout intersections are called "rotaries" and the state enforces that restriction. The term "traffic circle" is not used in the United Kingdom, where most circular junctions meet the technical criteria for "modern roundabouts". However, in some parts of the English Midlands, such as in Birmingham, roundabouts are commonly called "islands", which conflicts with the more generic use of the term "island" as a structure to divide traffic flow, and can cause confusion. In the Channel Islands a third type of roundabout, known as "Filter in Turn", exists. Here approaching drivers neither yield to traffic on the roundabout, as normal, nor have