The Role of Life Cycle Assessment in Reducing GHG Emissions from Road Construction and Maintenance
The United States has more than 2.65 million miles of paved public roadways that provide mobility and access to a range of users and facilitate the flow of goods and services upon which our economy relies. However, operating this extensive network (including construction and maintenance) comes at a cost. In 2008, roughly $182 billion was spent on highways alone. Most pavement surfaces need periodic maintenance and structures eventually need rehabilitation, the costs of which are often not considered when building new roads. There is also growing recognition of the environmental impacts from the use, construction, and demolition of our roadways.
Both public and private stakeholders are interested in reducing the environmental impact of pavements. To this end, life cycle assessment (LCA) has become an indispensable tool for guiding pavement engineering and management strategies because it considers the environmental impacts of all phases and uses of pavement. LCA for pavement involves modeling the system over its life cycle, calculating the flows of inputs (resources and materials) and outputs (air, water, and soil pollution), and calculating as well as interpreting the “cradle to grave” effects of the system’s impacts to people and the environment. When LCA is combined with life cycle cost analysis (LCCA), the most cost-effective approaches to reducing environmental impacts can be identified.