Second Severn Crossing
The Second Severn Crossing (Welsh: Ail Groesfan Hafren), officially named the Prince of Wales Bridge (Welsh: Pont Tywysog Cymru) since July 2018, is the M4 motorway bridge over the River Severn between England and Wales, opened in 1996 to supplement the traffic capacity of the Severn Bridge built in 1966. England’s National Highways operate the bridge. It has a total length of 5,128 metres (16,824 ft).
It is southwest of the Severn Bridge, and because it is more closely in line with the rest of the M4, it reduces the length of the journey between England and Wales. The junctions at each end are designed for most traffic to use this crossing, and to use the old Severn Bridge; 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. It is a cable-stayed bridge, whereas the Severn Bridge is a suspension bridge. The position of the bridge is close to that of the Severn Tunnel, which has carried the railway line beneath the river bed since 1886.
Much of the estuary is mudflats at low tide, but these can be covered by as much as 14 metres (46 ft) of water at high tide. This constrained the engineers: packets of work were scheduled at low tide and needed to be completed within the short windows allowed by the tides.
The concession given to the consortium that financed, built and operated the bridge required them to take over the original Severn Bridge’s outstanding debt and operate the two bridges as a single entity. The government sets taxes annually based on the previous year’s change in the Retail Price Index. On the expiry of the concession in January 2018, the consortium was required to hand the bridge over to public ownership. The tolls on both bridges were subsequently scrapped in December 2018.