Realizing the roads of the future

Abstract

Researchers are seeking simple ways to make asphalt pavements safer, quieter, and more eco-friendly . Roads encircle the globe in arterial networks that seem more pervasive each year. To some, they are a sign of progress; to others, they are a growing scar on the landscape. The United States alone hosts millions of miles of asphalt pavements, materials that aren’t particularly sustainable or good for surrounding ecosystems. Yet the United States and many other nations keep building and replacing the same sorts of roads year after year, using the same basic design that’s been around for centuries. We keep building and replacing the same sorts of roads year after year, using the same basic design that’s been around for centuries. But researchers and engineers have designs on some much safer, more sustainable pavements. Image credit: Shutterstock/Keith Homan. Despite humanity’s road-making rut, asphalt pavement upgrades are certainly possible. In recent years, researchers have started to work on a range of refinements that could make highways safer, quieter, and more sustainable. Modifications could include changing the aggregates and binders in the pavement or adding recycled materials into the mix. Even altering the pavement’s stiffness could improve the efficiency of vehicles using the road. Some of these changes could offer substantial reductions in the emissions of planet-warming CO2 and other pollutants. “There are all sorts of things that can be changed,” says Jeremy Gregory, a sustainability researcher at the Massachusetts Institute of Technology (MIT) in Cambridge. “We’re constantly looking for improvements.” Road design today is fundamentally the same as that used by the Romans. In general, a surface layer of pavement is laid atop thick layers of compacted granular materials that help transmit traffic loads to the underlying soil or bedrock. Modern pavement is typically made from either concrete, a mixture of …