Richmond, Va.—Experimental roads built and foundation of cot ton matting may soon carry Vir ginia motorists, Highway Com missioner H. G. Shirley said. The department, he explained, is preparing specifications for such novel construction at the sugges tion of the Federal Bureau of Roads. Cotton matting in sheets is laid in the partially completed road and her asphalt poured over it.The theory behind the construction is that the asphalt renders the mat ting waterproof, and thus prevents water seeping under the traffic sur face to freeze and crack in cold weather.