The Severn Bridge became a victim of its own success ….
The original Severn Bridge was built as a key part of the M4 linking South Wales to London and the southern counties of England. Following its opening in 1966, it became increasingly popular. By the early 1980s, traffic was severely congested in the summer and at peak times. It was anticipated that traffic would continue to grow significantly, which it did at a rate of up to 8% per year. High winds meant restrictions and the occasional closure of the bridge, with a long diversion via Gloucester.
Delays cost time and money and hinder development. Enhancing the link to South Wales was seen as both a physical and psychological requirement, to ensure that confidence in development would be sustained. In February 1984, the Secretary of State for Transport announced “a study into how a second crossing of the Severn Estuary might be provided in the general corridor of the existing bridge.” The completion of this study would avoid unnecessary delay in providing a second crossing as soon as it was needed.
The Study was completed in 1986 and, in 1987, the consultants were reappointed to develop the scheme. Project management was transferred to the Department of Transport’s South West office at Bristol, to be taken forward in consultation with The Welsh Office under the direction of a joint Steering Group. The original programme, set out in 1987/88, was to start works in 1992 with completion in 1996. The new crossing was completed to programme and to budget.