Perpetual Pavement

The Perpetual Pavement concept was first articulated in 2000 and the concept has rapidly gained acceptance. The APA’s newest technical document on the subject is Perpetual Asphalt Pavements: A Synthesis. This comprehensive publication captures the activities that have taken place over the last decade, synthesizes the information in way that is useful to providing guidance for Perpetual Pavement design and construction, and provides a vision for further research and development to refine Perpetual Pavements.

Since its inception, the Washington State Dept. of Transportation has been awarded three Perpetual Pavement Awards by the APA.


Smooth roads conserve energy and extend the life of pavements. Studies at a pavement test track in Nevada have shown that driving on smoother surfaces can reduce fuel consumption in the neighborhood of 4.5 to 5 percent compared to fuel consumption on a rough pavement. A study in Sweden concluded that vehicles traveling on the smoothest roads in that country’s network consumed up to 10 percent less fuel than vehicles on their roughest roads.

Smoother pavements also result in longer pavement life by as much as 10 to 25 percent, resulting in lower maintenance costs. As a rule, asphalt pavements are smoother than concrete pavements. Smoothness measurements on interstate highways in Oregon and Washington showed that asphalt pavements are on average 33 percent smoother in Oregon, and over 50 percent smoother in Washington.

Smoothness also means that truck tires don’t bounce on the pavement and deliver the kind of impact loading they would on a rougher pavement. Some experts estimate that increasing pavement smoothness by 25 percent results in a 9 percent to 10 percent increase in the life of pavements.

Smooth pavements save money for motorists, too. According to The Road Information Program, driving on roads in poor conditions costs around $400 per year per vehicle annually.

Construction Time

Paving with asphalt cuts construction project time significantly and eliminates the long curing times of concrete. As a result, traffic flows more smoothly, impact on commerce is minimized, and safety hazards are reduced.  Asphalt paving projects can be planned and carried out to take advantage of low-traffic periods, like nights and weekends, minimizing the project’s impact on motorists, residences and businesses.