What does the term “tracking” refer to in asphalt pavement?

The term “tracking” in asphalt pavement refers specifically to the deformation of the surface when vehicles drive over it. This can occur due to various factors, including the weight of the vehicles and the condition of the asphalt mix. When heavy traffic repeatedly travels over a specific area of the asphalt, it can lead to a change in the shape or contours of the surface, creating visible marks or ruts. This phenomenon is particularly common in areas with high traffic volumes and can negatively impact the ride quality and safety of the pavement.

The other terms presented do not accurately describe "tracking." Surface cracking relates to the development of fissures on the surface of the pavement, which is a different issue that can be influenced by factors like temperature changes and aging. Pothole formation is a separate problem caused by a combination of moisture infiltration and traffic load, leading to localized failures in the pavement layer. Surface layering pertains to the application technique of asphalt layers during construction rather than the deformation of an existing surface. Each of these issues can affect the performance of an asphalt pavement, but tracking is distinct in its focus on the deformation caused by traffic.