The Pavement Serviceability-Performance Concept

A system is described wherein the serviceability of pavements is rated subjectively by a panel made up of men selected to represent many important groups of highway users. Through multiple regression analysis a mathematical index is derived and validated through which pavement ratings can be satisfactorily estimated from objective measurements taken on the pavements. These serviceability indices (or the direct ratings) always refer to the conditions existing at the time the measurements (or ratings) are made. Performance of a pavement may then be determined by summarizing the serviceability record over a period of time. The system, developed at the AASHO Road Test, has potential for wide application in the highway field, particularly in sufficiency rating, evaluation of design systems, and evaluation of paving materials and construction techniques through the provision of an objective means for evaluation of performance.