No driver of a two (2) or three (3) wheel motor vehicle or bicycle shall carry any other person on, upon or within such vehicle on any street or highway in the city except as hereinafter provided; provided, however, that if any two (2) or three (3) wheel motor vehicle with a wheel diameter of twelve inches (12") or greater, or any bicycle shall have either a double seating device with double footrests or a sidecar attachment providing a separate seat space within such sidecar attachment for each person riding therein so that such person shall be seated entirely within the body of said sidecar, then it shall be permissible for an operator who has attained the age of sixteen (16) years or older to carry a passenger. A demonstration ride by a licensed dealer or his employee is excepted from provisions hereof. (1985 Code ch. 20 § 14-12)