This research analyzes the incidence and efficiency of impact deflectometry to evaluate and design the road reinforcements of a section of the central highway. For this study, a "non-destructive" methodology has been used, based on the collection, processing, and interpretation of the deflections measured on the road surface with the impact deflectometer equipment; these deflections reflect a response of the structural package under a given load, its measurement is simple, fast and "non-destructive," that is, we do not alter the structural package, and above all, we do not cause vehicular congestion as it would be with the conventional methodology. The deflections are analyzed using the back-calculation technique, which allows us to know the total Structural Number in the function of the characteristics of rigid pavement, obtaining a structural number Sn of 6.2 and 5.6 for the right and left the roadway, respectively. This research presents the results of the current condition of the road under study. It proposes a technique for calculating the Structural Number of an asphalt reinforcement on concrete from the back-calculation.