Many bridges constructed on Britain's transportation network are standardised, effectively off the shelf beam or truss designs. Whilst highly economical and practical, these bridges often lack visual merit or interest. Experience in the design and construction of the Tangmere Footbridge has revealed that for a small increase in overall budget, in this case 7% above a basic warren truss, a bridge can be transformed into a unique, interesting and characterful structure. One way of achieving this is with the use of architectural features. This approach however impinges on the controversial question of 'structural honesty' in regard to bridge aesthetics.
The paper explores several examples of structural dishonesty, as well as the logic and basis for the concept. Also discussed are the different emphases placed on design by engineers and architects, especially in relation to the visual impact of infrastructure on society. The paper concludes with a reflection on current practice regarding aesthetic bridge design, and makes some suggestions for developing and honing the skills of bridge designers.
Alistair Oliver, BEng (Hons), MSc, CEng, MICE
Mott MacDonald