Necessity of Including Maintenance Traffic Delay Emissions in Life Cycle Assessment of Pavements

Abstract

The Life Cycle Assessment (LCA) is a method which aggregates the environmental impacts associated within the life cycle of a pavement. Incorporation of LCA has been mostly focused on the emissions produced in the construction phase and in its constituents, such as material extraction and manufacturing, hauling of materials, etc. Less emphasis has been given to emissions caused by traffic delays during maintenance operations due to lack of well-defined methodology and unfamiliarity about the magnitude of these emissions. In this study, an approach is proposed to include traffic delay emissions by combining Users Cost approach of Life Cycle Cost Analysis (LCCA) with Motor Vehicle Emissions Simulator (MOVES 2014) developed by the United States Environmental Protection Agency (US EPA). The LCA was performed for four different pavement designs and their Global Warming Potential (GWP) were included in the assessment. The GWP of the four designs with and without considering traffic delay emissions (in carbon dioxide equivalents: CO2e) were 53, 51, 50, and 22 versus 6.1, 4.5, 4.3, and 13 thousand tons per mile, respectively. The differences between the GWP with and without traffic delay emissions suggests that there is a need to include traffic delay emissions in the LCA to better estimate environmental impact.