Life-cycle greenhouse gas emissions associated with a highway reconstruction: a New Jersey case study

• A life-cycle greenhouse gas emissions analysis of a major road reconstruction was conducted.
• Materials, construction equipment, mobilization, traffic disruption and life-cycle maintenance evaluated.
• Most emissions are from upstream materials production, traffic disruption was minor for this project.
• Non-CO2 emissions account for a substantive share of total emissions.
• Over a 50-year lifetime, about 20% of emissions associated with road reconstruction.

A comprehensive greenhouse gas (GHG) life-cycle assessment was conducted for a large highway reconstruction project in New Jersey. The GASCAP model was used to determine the total life-cycle GHG emissions associated with the materials used, construction equipment, mobilization of resources for the project, traffic disruption during construction, and materials used for life-cycle maintenance. The focus of the case study was to determine the relative share of these various components, as well as the importance of accounting for non-CO2 GHG emissions. Results suggest that non-CO2 emissions are substantial enough that they should be included and that various smaller material components, not just those associated with materials in the pavement should also be included. For this specific case-study, traffic disruption was a minor component of total emissions, though this result will differ depending on project and road network details. GHG emissions associated with this reconstruction project account for about 20% of the total emissions expected to be generated from traffic using the highway over a 50 year lifetime.