Post-construction Changes
In January 1977, it was announced that bridge traffic would be restricted to a single lane in each direction following the discovery of several weaknesses in the ten year old structure. The lane closures would last for several months.
The Severn Bridge crossing was strengthened and resurfaced in the late 1980s as the weight of traffic grew. The work included the strengthening of the Severn Bridge towers and deck, an extension to the existing Wye Bridge towers and the replacement of the original single stays with two stays. The open structure of the new stays is designed to facilitate maintenance. Most of the strengthening work was inside the deck box and towers and so is not visible. The surfacing is a 35 mm (1.4 in) thick layer of mastic asphalt over an acrylic waterproofing membrane.
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