The original Severn Bridge opened in 1966, carrying the M4 across the River Severn. The Second Severn Crossing opened 30 years later, and the M4 was diverted to cross it. The loop of motorway that includes the original bridge (previously part of the M4) is now the M48, and a new motorway (the M49) was built from the M5 at Avonmouth to link with the Second Crossing (about one kilometre from where it actually begins to cross the river).
The main point of the M48 and the original bridge is now to serve Chepstow, and the west bank of the Severn going northwards.
Tolls were originally collected on both crossings, from vehicles travelling in a westward direction only, but were scrapped in 2018.
© Haydn Thompson 2017–22