As the Shropshire county surveyor, Telford was also responsible for bridges. In 1790 he designed a bridge carrying the London–Holyhead road over the River Severn at Montford, the first of some 40 bridges he built in Shropshire, including major crossings of the Severn at Buildwas, and Bridgnorth. The bridge at Buildwas was Telford's first iron bridge. He was influenced by Abraham Darby's bridge at Ironbridge, and observed that it was grossly over-designed for its function, and many of the component parts were poorly cast. By contrast, his bridge was wider in span and half the weight, although it now no longer exists. He was one of the first engineers to test his materials thoroughly before construction. As his engineering prowess grew, Telford was to return to this material repeatedly.