The council is hereby authorized to adopt and amend by law, whenever it shall deem the same necessary to promote the public safety and welfare, regulations concerning the obstructing or the placing upon the surface of public sidewalks, streets, curbs, gutters and other public rights-of-way, any objects for the purpose of display, advertisement, sale, rent or related purposes. (Mont. Co. Code 1965, § 16-10; 1970 L.M.C., ch. 8, § 4.)