Asphalt pavements have demonstrated outstanding performance across the spectrum of traffic loadings and conditions. Asphalt is by far the most popular pavement material for low- and medium-traffic roadways, and has proven itself over time under heavy truck traffic in urban and rural settings. Even under 4heavy, static, and channelized loadings such as those at port facilities and commercial airports, asphalt pavements have provided excellent service.
In heavy-duty highway pavements, asphalt is often the pavement of choice such as I-695, the Baltimore Beltway, which has an annual average daily traffic (AADT) of 215,000 vehicles. The Washington D.C. Beltway (I-495), Atlanta’s I-285, San Antonio’s loop I-410, and I-80 in Oakland are all examples of high-traffic roadways where asphalt was selected as the pavement type of choice. The Baltimore- Washington International (BWI) Airport, the Port of Seattle, and the Port of Portland, Oregon are examples of heavy-duty asphalt pavements subjected to extreme loads. It should be noted that the BWI Airport was presented with a Perpetual Pavement Award from the Asphalt Pavement Alliance in 2002 for two long-life asphalt runways that are now (in 2010) over 60 years old.
Many technological improvements in asphalt pavements have been made in order to handle increased loads. These improvements have included the introduction of polymer-modified binders, the development of Superpave binders and mix design, and the introduction of stone-matrix asphalt (SMA) as a premium surface material.