Sec. 19. (a) Whenever any bridge is constructed or acquired under this chapter, and the cost thereof paid in whole or in part from the Indiana interstate bridge fund, it shall be the duty of the authority (except in the case of a bridge constructed or acquired under authority of section 21 of this chapter) to fix, maintain, and collect tolls for the use of such bridge from the time of the completion thereof in accordance with section 16 of this chapter.
(b) All revenues from a bridge in excess of those required by section 16 of this chapter shall be applied to reimbursement of the Indiana interstate bridge fund in the order and manner provided so that such funds may be fully reimbursed as rapidly as the revenues of such bridge permit.