Pavement engineers have been producing long-lasting asphalt pavements since the 1960s.
Research has shown that well-constructed and well-designed flexible pavements can perform for extended periods of time. Many of these pavements in the past forty years were the products of full-depth or deep-strength asphalt pavement designs, and both have design philosophies that have been shown to provide adequate strength over extended life cycles (APA, 2002). It is significant that these pavements have endured an unprecedented amount of traffic growth. For instance, from 1970 to 1998, the average daily ton-miles of freight increased by 580 percent, and the average freight loading continues to increase 2.7 percent per year.