ABSTRACT
The performance of unpaved roads is directly affected by environmental stresses such as wind, rain, water, frost, as well as mechanical stresses from vehicle tires, heavy axle loads and traffic volumes. The characteristics and mineralogy of granular materials used as surfacing material also play a key role in road performance. A combination of these factors may cause surface distress such as rutting, corrugation, potholes and erosion amongst others, which can affect user comfort and safety. Therefore, maintenance work such as grading must be carried out on a periodic schedule to maintain the pavement serviceability to an acceptable level. These maintenance costs represent a major expense for those who manage unpaved road networks.
