A Project Based Framework for Assessing and Monitoring Highway Construction Greenhouse Gas Emissions

Motivated by the need to address challenges of global climate change, this study develops and implements a project based life cycle assessment framework that can be used to estimate the carbon footprint for typical construction work-items found in highway reconstruction and rehabilitation projects. The proposed framework considers the life cycle emissions of products and processes involved in the raw material acquisition and manufacturing phase, and the pavement construction phase. It also accounts for emissions due to vehicular use and maintenance operations during the service life of the pavements. The framework introduces methods based in life cycle assessment to (i) develop project emission inventories for highway construction, rehabilitation and maintenance projects, (ii) analyze the inventories to calculate project level construction emission estimation metrics. Fourteen highway construction and rehabilitation projects in the State of Michigan were used to implement the method and validate the analysis approach. In addition, the paper introduces the Project Emissions Estimator (PE-2) - a web based tool that can be used to estimate and benchmark the CO₂ footprint of highway construction projects. The contribution of this research is that it furthers our understanding of pavement life cycle assessment methods while providing an emission estimation tool that can be used by decision-makers to monitor and assess project emissions.