A new method for evaluating the sustainability of bridges

Civil infrastructure projects such as bridges can have a major impact on many of the issues relevant to sustainability and it is therefore important that civil and structural engineers have methods at their disposal that will help them deliver sustainable designs. This paper describes a new model for appraising the sustainability of bridges. The indictors used to assess sustainability are climate change, resource use, waste, biodiversity and heritage, noise, dust, vibration, aesthetics, employment and businesses, construction costs, maintenance costs and user delay costs. The paper describes the aim of each indicator and provides details of the methods of measurement. The paper also presents the results of a case study on the appraisal of three alternative designs of an over-bridge for a dual two-lane motorway to discover which option is the most sustainable. Details of the key input parameters are provided. The way in which individual impacts are combined to produce an overall sustainability score for a given structure is highlighted. The paper concludes with a discussion on interpreting the results and ways of further improving the sustainability of the selected design.