Asphalt is used as a pavement surface for all types of traffic requirements. Applications include low-volume roads, high-volume roads, airfields, bus lanes, toll booths, intersections, and industrial areas. Not only does traffic vary widely, asphalt pavements must also perform in weather extremes ranging from the very hot to very cold conditions. Each different application places different demands on the pavement and requires some minimum properties for satisfactory performance.

One of the most important requirements for good mix performance is rut resistance. Ruts may occur in asphalt if the mixture is improperly designed or constructed. A rut is defined as a depression in the wheel path of an asphalt pavement.

For given weather conditions, there are two main factors which affect rutting. The first factor is the number of heavily loaded trucks: the more trucks, the more resistance to rutting is required. The second factor is the speed of traffic: pavements carrying slow moving or stopped traffic require more rut resistance than pavements carrying fast moving traffic. Therefore, asphalt mixes used in intersections, bus stops, and toll booths must meet the demands of traffic weight, speed, and volume.

Select the link for additional information and to access a case study from the Asphalt Institute on High Performance Intersections.