Application of Greenroads Rating System and Life Cycle Assessment in Informing the State of the Practice in Sustainable Roadway Construction

This paper highlights the application of the Greenroads Rating System in collecting, measuring, and communicating sustainable best practice data in the context of roadway infrastructure construction. Once measured, meaningful comparisons between common practice and what goes above and beyond routine can be recognized, educated, advertised, spread, and finally, implemented. This study collected, organized, and analyzed data from 33 Greenroads-certified roadway construction projects completed between 2011 and 2018 with a total value of over 2 billion USD. We believe such a database is scarce within the literature and is worth exploring. Greenroads scorecards, which indicate the level of achievement in sustainable construction practices, were analyzed to show the frequency with which best practices are pursued. Findings show that projects typically perform activities that can be considered common practice and avoid activities that fall outside of their prior experience realm. Realizing that roadway surfaces including pavement structures often contribute to a high proportion of a roadway project’s sustainability efforts, the last piece of this study is dedicated to the life cycle assessment (LCA) of paving materials as conducted and reported by project teams. Integrating LCA results with financial information from pay item lists, correlation analyses between carbon and energy footprints and the price of major paving materials such as asphalt mixtures and portland cement concrete were carried out. Results show that the quantified environmental footprints of projects and the materials used to build them strongly correlate with the total price of projects and the price of constituent materials, respectively.