The U.S. network of streets, roads, and highways consists of 8 million lane-miles, requires 350 million tons of materials annually for maintenance and construction, and supports more than 3 trillion vehicle-miles annually.

This network has major environmental and economic impacts. It also has a high energy demand, not just in constructing and maintaining the system, but from the cars and trucks that use it. Roads account for 83% of emissions from the transportation sector and  27% of all greenhouse gas emissions in the U.S.

Because of the high impact of pavements, there is growing interest in the ability to better quantify their performance. To address this, researchers at the Massachusetts Institute of Technology’s (MIT) Concrete Sustainability Hub conducted a life-cycle assessment (LCA) study to evaluate and improve the environmental impact of pavements.

The study is a major development for construction-related life-cycle assessment because it thoroughly examines the cost and environmental impacts for the full life of pavements - including the use and operations phase - not just the costs and embodied CO2 that occur at initial construction. Currently, most LCAs do not fully account for these impacts, which can include traffic delays, energy consumption, and maintenance.