The report presents a new concept for the design of asphalt pavements in Arizona. The criteria for design are based on fatigue response of a selected 3-layered system to tensile stresses in the asphaltic surface course and to vertical compressive strains in the subgrade. These values of stresses and strains are calculated using elastic theory and Chevron's computer program. A new classification of highway loads is presented and environmental effects on stresses and strains are accounted for by the influence of regional temperature and rainfall on the moduli of the surface and subgrade. The new design procedure is illustrated using actual design data and the results obtained are compared to designs obtained by Arizona, Kansas, Texas and Shell procedures.