A methodology to facilitate the environmental comparison of bridge management strategies

Highway bridge management is traditionally influenced by technical and socioeconomic constraints. More recently, reflecting the changing perceptions of society and concerns that now exist towards sustainability, bridge owners are increasingly looking to integrate sustainable decision-making into their operational frameworks. As a consequence, the sector requires a knowledge base of environmental information and the tools and techniques with which to evaluate the environmental performance of its activities. Given this context, the objective of the research described herein has been to develop a life cycle based system which can improve understanding and deliver insights into the environmental impacts of alternative bridge management strategies. This objective has been achieved and a methodology to investigate the environmental performance of highway bridge infrastructure has been produced. The “framework” that has resulted is structured around a process that identifies structural form, design, construction materials and service life management strategy as aspects of importance. To facilitate investigation a comprehensive and codified dataset for each variable has been developed. This is founded on the structure inventory and management practices of Surrey County Council. Additional input from other UK bridge owner groups has also been provided. The approach applies the environmental management tool Life Cycle Assessment (LCA) to generate impact information and disseminate findings using a single environmental index. In use, the framework provides a process for completing environmental investigation and a method to examine the environmental performance of alternative structural designs and management approaches. The functionality of the system methodology has been tested by the completion of three bridge LCA investigations. These demonstrate that an effective framework with which to plan, undertake and complete an environmental investigation of highway bridge infrastructure has been developed. Additionally, study findings have provided a valuable understanding of the environmental performance of alternative structural forms and designs, materials of construction and structural management strategies. The assessment methodology represented herein presents an entirely new agenda for the bridge management sector. It provides a bespoke process for developing quantitative environmental information of highway bridge infrastructure and structural management approaches. As bridge owners broaden their decision-making criteria and include environmental impact alongside more established decision influences, this framework and the methodology it represents can help to deliver more sustainable bridge management strategies.