A newly developed parameter identification procedure for pavement structures that uses the falling weight deflectometer (FWD) test is presented. The procedure involves the development of both forward and inverse models. The spectral element technique is used for the formulation of the forward model. The spectral element contributes to the efficiency of the procedure because (a) it is able to describe a whole material layer by one element, which makes the system of equations very small, and (b) it is able to describe the transfer functions of the system exactly. The latter assists in the development of an efficient objective function for the inverse model. Some aspects of the formulation of the inverse model are presented. Two case studies that address use of the procedure for FWD data harmonization and the accuracy and robustness of the procedure are examined.