A gatekeeper on any toll bridge without an electronic toll collection system, as defined in § 17-16D-2 of this code, shall keep such money of small denomination on hand, as may reasonably be required in the ordinary course of business, for making change for passengers, and it is the duty of passengers to offer money for passage of a denomination as near as possible to the amount charged for such passage. This section shall not apply to persons now having a lawful right to pass on such bridge without the payment of toll.