Severn Viaduct

Shrewsbury in Shropshire is celebrated as a beautiful and historic town, but it is perhaps less well known as the birthplace of the famous English naturalist, Charles Darwin. In 2018, Knight Architects was invited to develop an ‘enhanced design’ for a highway crossing of the River Severn, as part of the Shrewsbury North West Relief Road project, which celebrated Darwin and drew upon the relationship between the man and his origins.

The alignment of the new three-lane highway traces a long plan curve as it rises from the low-lying floodplain up to high ground at Shelton, resulting in a viaduct of 260m in length and a continuous gradient of 6%. A concept design was developed to represent the notion of evolution, with the bridge supports evolving from a simple column to increasingly tall Y-piers, as the height above ground increases. The design also evokes Darwin’s theory of the Tree of Life and offers a distinctive and memorable elevation, visible from afar across the open countryside.

The challenge created by the steep highway was equally important to the safety and enjoyment of pedestrian and cycle users. The concept design explored a dedicated shared path, protected from the adjacent traffic, with rest points and interpretation of the views towards Shrewsbury. The design was well received by the Project Board, but a decision was taken in December 2019 to progress with a ‘functional structure’.