page_title: Second Severn Crossing
section_title: Design
hierarchical_section_title: Second Severn Crossing / Design
caption_attribution_description: English: The second Severn Bridge A view of the second bridge shot from the first bridge
context_page_description: The Second Severn Crossing —officially renamed the Prince of Wales Bridge —is the M4 motorway bridge over the River Severn between England and Wales, inaugurated on 5 June 1996 by the Prince of Wales to supplement the traffic capacity of the Severn Bridge built in 1966. The bridge is operated by Highways England. In 2018 the bridge was renamed the Prince of Wales Bridge.
  The Second Severn Crossing marks the lower limit of the River Severn and the start of the Severn Estuary. It is further southwest than the Severn Bridge and because it is closer in-line with the landward sides of the M4, it reduces the length of the journey when travelling between England and Wales. The junctions at each end are designed for most traffic to use this crossing, and in order to use the old Severn Bridge crossing, one has to leave the M4 at junction 21 and join the M48 near Aust or at junction 23 near Magor. The new crossing carries more traffic than the Severn Bridge, which is still in use. It is wider than the Severn Bridge, having three lanes and a narrow hard shoulder each way, compared to the two lanes, cycle path and narrow footpath of the original crossing.
context_section_description: The chief architect of the bridge was Ronald Weeks of the Cardiff based Percy Thomas Partnership, with the detailed engineering design by the Halcrow Group and the French consultancy SEEE. The bridge has portals close to Sudbrook, Monmouthshire on the Welsh side and Severn Beach in South Gloucestershire on the English side. It has three principal sections – a 25 span viaduct on the English side of length 2,103 m (6,900 ft; 1.307 mi), a 24 span viaduct of length 2,077 m (6,814 ft; 1.291 mi) on the Welsh side and the bridge itself, a 948 m (3,110 ft; 0.589 mi) structure with a 37 m (121 ft) navigational clearance, giving a total length of 5,128 m (16,824 ft; 3.186 mi). The central section, called the Shoots Bridge, is of cable-stayed design and the central span (between the bridge pylons) is 456 metres (1,496 ft) in length. The approach viaducts are of a segmental bridge design. The crossing forms a very slight "S" curve – the roadway has an approximate east-west alignment at each of the portals, while the central bridge follows an alignment approximately WNW to ESE.
  The Severn Railway Tunnel passes under the estuary bed on a line which is generally about 500 m upstream of the bridge, but which passes under the line of the bridge close to the English shore.
  The deck, which carries three lanes of traffic in each direction, is 34.6 metres (114 ft) wide. The sides of the bridge are fitted with 3 metres (9.8 ft) baffle plates to reduce lateral wind loads coming from the Severn Estuary onto the traffic; this has reduced the number of times that speed restrictions have been needed. The overall design of the new crossing makes it more resistant to high winds than the old Severn Bridge.
caption: The Shoots Bridge; the shipping channel lies between the two towers
exif: {}