Automobile transporters shall not exceed a length of 65 feet when operated on any interstate highway or on any highway designated by the Commonwealth Transportation Board and stinger-steered automobile transporters shall not exceed a length of 80 feet when operated on the national network of interstate and primary highways as defined in 23 CFR 658.5, as amended. Any such vehicle shall display a sign of a size and type approved by the Commissioner of Highways warning that the vehicle is an over-length vehicle. Notwithstanding the provisions of § 46.2-1120, a four-foot overhang shall be allowed beyond the front and a six-foot overhang shall be allowed beyond the rear of the vehicle. Such combinations shall have reasonable access to terminals, facilities for food, fuel, repairs, and rest as designated by the Commissioner of Highways.