The objective of this research is to establish the technical engineering and cost analysis concepts that will enable WisDOT management to objectively evaluate the feasibility of switching construction specification philosophies for aggregate base. In order to accomplish this goal, field and laboratory testing programs were conducted on existing HMA pavements and on base layers under construction as well as comprehensive survey was conducted on highway agencies practices pertaining to base layer construction in the U.S. and Canada. This research proposed construction specifications for aggregate base course layers.