PURPOSE: To obtain a road pavement structure having a sufficient water- rataining and adjusting function and a sufficient strength, by superposing a pressure-resistant layer internally holding aqueducts and a water-rataining space enclosing water spray tubes, under the surface course of the road.

CONSTITUTION: Concrete vessels opened at their tops are arranged to be adjacent to each other so as to form a water-retaining space 8. Rain water penetrating in the surface course 1 from joints is led through a water-permeable base course 2 composed of gravels or the like to aqueducts 5 opened below the base course 2 and evenly discharged from a number of spray holes provided on the front end of aqueducts 5 into the water-retaining space 8. This rain water is once reserved in the water retaining space 8 and thereafter, poured into the subgrade through the lower second water-proof layer 11 in accordance with the water quantity retained on the subgrade. The water retaining space 8 serves not only to support the base course as its original mission but also to reserve water and adjust the outflow and hence, it prevents the subgrade from softening due to excess water content in the subgrade and breaking of a subbase course due to a localized torrential downpour.