To solve an environmental problem and a problem of shortage in fields for treating wastes by reclaiming dug soil and the concrete lumps, asphalt lumps and construction surplus soil of construction wastes as a roadbed material, while the dug soils of road construction have been scraped in specified waste- treating fields as wastes and while natural fractures and resource exhaustion due to the collection of road materials are serious.

This roadbed material is reclaimed by adding the concrete lumps or asphalt lumps of construction wastes or the mixture of the concrete lumps and the asphalt lumps to dug soil, crushing the mixture, adding quicklime to the crushed product, screening the mixture into granules having granule diameters of 40 to 20 mm, granules having granule diameters of 20 to 2.5 mm and granules having granule diameters of 2.5 mm to 0 mm, and then mixing the granules in a prescribed ratio.