Commonwealth of Kentucky has been using the Road Rater since the early 1970's for research purposes and pavement evaluations. Procedures were developed to determine elastic modulus of subgrade and effective thickness os asphaltic concrete pavement. These procedures have remained relatively the same since the early 1980's and the 2-3 project method is currently used to desing overlay thickness. This paper proposes an approximate Falling Weight Deflectometer (FWD) analysis by Dynamic Slab-Ground Theory (DSGT) and the design procedure of overlay thickness.