Asphalt Mix Designs vary depending on the environmental conditions and the anticipated traffic loads or ESAL’s (Equivalent Single Axle Loads) anticipated over the lifetime of the project. The amount of ESAL determined the level of the mix design and the environmental conditions determine the Performance Grade of the oil to be specified. For example, a Highway asphalt mix design would have dramatically different blends of aggregate and oil than a homeowner’s driveway due to the significantly different anticipated ESAL’s. The grade of oil is determined by the high and low temperatures of the anticipated climate. An oil used in southern Arizona will be vastly different than the oil used in Northern Montana. Finally, the type and percentage of recycled material used affects the amounts of virgin aggregate and oil needed in the mix design.