Currently, the porous asphalt mixture is used for the surface course of pavements on many highways in Japan. Damage called "stripping," where the asphalt peels off from the aggregate, caused by rainwater infiltrating through the surface course, has occurred in the binder course beneath the surface layer formed by the porous asphalt mixture. If this type of damage occurs, partial subsidence will often appear on the surface course of the pavement. Road inspections on highways in Japan evaluate the soundness of the road surface by checking 3 indices (the amount of rutting, crack rate, and International Roughness Index). It is difficult to quantitatively capture and evaluate partial subsidence caused by stripping of the binder course beneath the porous asphalt surface layer with these check items. Therefore, we have developed a new index “5mσmax” to evaluate the partial subsidence. This index is derived from the transverse profile data of the road surface, measured by the road surface condition measurement vehicle. This index can predict the occurrence of partial subsidence in one to two years. Therefore, this index can be used in road surface management and repair planning.