Prince of Wales Bridge

The Prince of Wales Bridge carries the M4 motorway over the Severn Estuary between England and Wales. Opened in 1996 as the Second Severn Crossing, it now links Sudbrook in Monmouthshire with Severn Beach in South Gloucestershire. The bridge is a cable-stayed structure with a central span of 456 metres and a total length of more than five kilometres. Its approach viaducts on both sides rest on dozens of concrete piers that rise from the mudflats. At low tide the estuary floor is exposed, while high tides bring up to fourteen metres of water beneath the deck. Engineers chose a cable-stayed design to handle the estuary’s extreme tides and strong currents. The bridge carries three lanes in each direction and includes narrow hard shoulders for breakdowns. Wind baffles along the sides reduce the lateral loads that once forced speed limits on the older suspension bridge. Beneath the deck, a narrow monorail train runs the full length for maintenance access, stopping at stations inside the pylons and at inspection gantries. Visitors driving across see the wide estuary stretching on either side, its channels marked by buoys. On the Welsh side the approach curves gently through farmland near Sudbrook, while the English approach passes close to the Severn Beach shoreline. The bridge’s slight reverse-S curve keeps traffic flowing without sharp bends, and the central span clears the navigable channel known as The Shoots. From the deck the shifting colours of the estuary and distant hills of the Forest of Dean create a changing panorama.