The General Assembly finds and declares that outdoor advertising signs, displays, or devices which are located more than six hundred sixty feet (660') off the nearest edge of the right-of-way, located outside of urban areas, visible from the main-traveled way of the interstate, primary, or other state highway designated by the State Highway Commission, and erected for the purpose of their messages being read from the main-traveled way and which do not conform to the provisions of this subchapter are nonconforming advertising devices; therefore, the right is conferred upon the commission to enforce the provisions of this subchapter by means of restraining order, mandatory injunction, or other appropriate remedy for the abatement of nonconforming advertising devices, displays, or signs.