Full-Depth or Deep-Strength Asphalt Pavement
These almost 50-year-old projects were the product of full-depth or deep-strength asphalt pavement designs. Both of these design strategies have proven to provide a stable pavement over an extended lifecycle of the project, and it is important that the asphalt pavement is able to remain strong over a long period of time.
Full-depth pavements place asphalt layers on soil. Deep-strength asphalt pavements are constructed by setting asphalt layers on a thin granular base. These construction methods have allowed pavement to meet growing demands.
Traffic in the United States has steadily grown since the 1960s. A study found that the average daily ton-miles of freight increased by 580 percent in the thirty years after the 1960s. Since then the grown of freight continues to grow at an average rate of 2.7 percent per year. This growth in the amount of freight puts a heavy strain on the pavement supporting it.
While the amount of freight has increased the leave of funding for public road projects has decreased. The lack of funds means that supporting increased freight only occurs through the efficient design of new paving projects, and the improvement the paving materials. The increase in traffic also causes most construction projects to be undertaken with minimal interruption of traffic.