The provisions of § 32-38-1 do not apply to:
(1) Any occupant of a passenger vehicle manufactured before September 1, 1973;
(2) Any occupant of a passenger vehicle who possesses a written statement from a doctor licensed under chapter 36-4 or 36-5 that the individual is unable for medical reasons to wear a safety seat belt system;
(3) Any occupant of a vehicle not equipped with a safety seat belt system because federal law does not require that vehicle to be so equipped; or
(4) Any rural carrier of the United States Postal Service while serving his rural postal route or any person delivering newspapers or periodicals on an assigned home delivery route.