The 15 m to 45 m (50 ft to 148 ft) span range is representative of the majority of bridges encountered in motorway, principal and trunk road schemes. The difference between an expensive and an economical bridge originates from a few very simple decisions at the design stage. The purpose of the paper, therefore, is to offer a few suggestions at a practical level the adoption of which should generally lead to economic solutions for the more regular bridge situations.
M.V. Woolley