Anyone who’s driven over the potholes that appear on America’s roads and highways every spring knows that road surfaces require continual upkeep. This fragility has prompted the asphalt industry to consider new ways to extend the useful lives of roads, including the concept of “perpetual pavement.” This three-layer pavement design consists of a durable surface layer, a rut-resistant intermediate layer, and, most crucially, a flexible, crack-resistant base layer. The base layer often incorporates a high content of liquid asphalt binder to provide flexibility under the strain of constant, heavy traffic.
Although this three-layer asphalt road structure has been around for decades, it wasn’t until 2000 that the Asphalt Pavement Alliance coined the Perpetual Pavement term and formalized its design and construction guidelines. Higher initial construction costs have limited adoption of this type of road, but Perpetual Pavement offers a number of advantages that can more than offset those costs.
Long Life, Low Maintenance, & Other Key Benefits
Despite its hyperbolic name, Perpetual Pavement isn’t quite perpetual. Roads built with this design, however, can last fifty years or more, with only the surface layer requiring routine maintenance. The flexible base layer resists cracking, which is the cause of much costly, labor-intensive road repair and reconstruction. Despite a higher initial cost than a conventional pavement design, Perpetual Pavement is more economical in the long run, often providing from 4% to 20% in cost savings over its lifetime, which can be a relief to cities concerned about the availability of government infrastructure funds. In a study of a section of road in Ontario, Canada, the Perpetual Pavement portion netted a 6.6% cost savings over its life compared to the conventionally paved part.
Apart from a long life and appealing life cycle costs, Perpetual Pavements also have a reduced environmental impact compared to traditional pavements, since less asphalt and other resources are required to maintain a Perpetual Pavement-based road over its lifespan. As a result, weeks-long lane closures and detours can be substantially minimized since the routine repairs to the asphalt surface can be accomplished quickly and easily - sometimes overnight.
Perpetual Roads Are Found Throughout America
The Perpetual Pavement concept has been utilized throughout the US. For example, in Oklahoma City, two sections of Interstate 40 were built with this design in 1967, long before the Perpetual Pavement name and concept were formally recognized. One of these highway sections only required resurfacing after twenty years. In Missouri, at least four roads feature this construction, and Perpetual Pavements have been used in numerous other states such as Alabama, California, Florida, Kansas, Maryland, Minnesota, Ohio, Washington, and Wisconsin.
Where to Find Out More
Need more information? For historical demand data and forecasts by product, application, and US region, see Paving Asphalt Market in the US and Asphalt Market Forecasts, two industry studies published by The Freedonia Group. These studies also discuss market environment factors, industry structure, company market share, and leading companies.
About the Author
Joseph Iorillo is a researcher and writer at The Freedonia Group, where he contributes to studies on a wide array of topics, including consumer and industrial goods, chemicals, and packaging.