Integrated Life Cycle Analysis of Cost and CO2 Emissions from Vehicles and Construction Work Activities in Highway Pavement Service Life

Abstract

In this study, we aimed to provide a practical method to estimate the economic and environmental impact of vehicle and work activities throughout the entire service life of a pavement area to support pavement management strategies and decisions. To achieve this, we integrated two key life cycle analysis methods, life cycle assessment (LCA)) and life cycle cost analysis (LCCA). The integrated model not only considers CO2 emissions associated with the four main modules—the materials module, the work activities module, the work zone module and the usage module—mentioned in LCA, it also considers agency costs and user costs related to highway usage, work activities, work zone traffic delays and detours in the LCCA process. We used detailed and integrated methods to compute CO2 emissions and costs based on the four modules and two components of agency and users mentioned above. A case study based on a real freeway project in China was used to verify the applicability of the integrated model. The results of the application of the integrated LCA-LCCA model indicate that maintaining the typical activity profile could be beneficial in terms of both CO2 emissions and cost, with savings of 36.8 ton/lane/km of CO2 emissions and 10,530 USD/lane/km (in 2007 dollars) representing the total benefits during the pavement’s service life. This means that timely maintenance could help to achieve savings in terms of financial costs and CO2 emissions simultaneously.