Load limits based on rutting in pavement foundations

Road agencies worldwide are given to impose restrictions on the size and weight of vehicles for protecting their pavement infrastructures. While easy to implement, many are posted with a gross vehicle weight (GVW) restrictions. It is also recognized that the gross load from a vehicle is transmitted through the axle tires. Thus, the tire loads and the geometric arrangement of the tires comprising the axle are the factors that more directly influence the response of the pavement to the vehicle rather than its gross weight. Indeed, a vehicle may be in compliance with the GVW limit but still be damaging because of axle loads that exceed the pavement's structural capacity. A better understanding of the complex interactions between pavement performance and the factors related to axle loads, type, pavement structure, and material characteristics should be taken into account. In this paper, a methodology for establishing rutting performance-based load limits in conventional flexible pavements (CFP) is presented.