§ 81.03 DOUBLE RIDING RESTRICTED.
   A person propelling a bicycle shall not ride other than astride a permanent and regular seat attached thereto. No bicycle shall be used to carry more persons at one time than the number for which it is designed and equipped.
(Iowa Code §§ 321.234(3), 321.234(4)) (1999 Code, § 76.03) Penalty, see § 10.99