Development of framework for implementing sustainability in bridge projects with greenhouse gas (GHG) emissions calculation guidelines based on LCA methodology implementations

A bridge constitutes a large investment of capital, materials, and energy and is associated with significant social, economic, and environmental impacts. Application of sustainable practices for bridge design, construction, and maintenance can enable an environmentally responsible and effective use of resources for this large investment. The focus of this study is to develop a framework that will assist transportation engineers and managers in developing more sustainable design and construction processes for new bridges, and sustainable maintenance practices for existing bridges. This framework consists of a green rating system, which is divided into three categories, which are design, construction, and maintenance. The last two sections are further divided into various criteria. For each criterion the description, intent, and requirements have been established. The requirements are established based on various industry standards such as the Environmental Protection Agency (EPA), American Association of State Highway and Transportation Officials (AASHTO), Federal Highway Administration (FHWA), LEED®, and current bridge engineering standards. The certification levels for the rating system are established based on research panel discussion and interview with MDOT experts to categorize sustainable bridges. A bridge can be categorized as Non-Green, Certified, Green, Total Green, and Evergreen, depending on the total score obtained by the bridge project. Guidelines were developed to estimate GHG emissions in bridge projects based on LCA methodology to evaluate the framework and investigate strategies that attempt to reduce GHG emissions supporting sustainable decision-making.