(a) It shall be unlawful for any person under the age of 14 years to ride on any vehicle or upon any portion thereof not designed or intended for use of passengers when the vehicle is in motion.

(b) It shall be unlawful for the operator of any vehicle to allow any person under the age of 14 years to ride on any vehicle or upon any portion thereof not designed or intended for the use of passengers when the vehicle is in motion.

(c) This section shall not apply to:

(1) An employee under the age of 14 years engaged in the necessary discharge of the employee’s duty within truck bodies in space intended for merchandise or cargo; or

(2) when the vehicle is being operated in parades, caravans or exhibitions which are officially authorized or otherwise permitted by law.

(d) The provisions of subsections (a) and (b) shall apply only when a vehicle is being operated within the corporate limits of a city or on the state highway system.