815 ILCS 415/5
That it shall be the duty of the owner or owners of railroad or steamboat, by their agents or managers, to provide for the redemption of the whole, or any parts or coupons of any ticket or tickets, as they may have sold, as the purchaser, for any reason, has not used, and does not desire to use, at a rate which shall be equal to the difference between the price paid for the whole ticket and the cost of a ticket between the points for which the proportion of said ticket was actually used; and the sale by any person of the unused portion of any ticket otherwise than by the presentation of the same for redemption, as provided for in this section, shall be deemed to be a violation of the provisions of this act, and shall be punished as is hereinbefore provided: Provided, that this act shall not prohibit any person who has purchased a ticket from any agent authorized by this act, with the bona fide intention of traveling upon the same, from selling any part of the same to any other person.
815 ILCS 415/5