(a) The department periodically shall transfer cash received in the state highway fund to the highway tax and revenue anticipation note fund to ensure the timely payment of the notes.
(b) On payment of all outstanding notes, rebates to the federal government, and costs of issuance, the department shall transfer to the state highway fund any amounts remaining in the highway tax and revenue anticipation note fund. If amounts credited to the highway tax and revenue anticipation note fund are insufficient to pay principal, any premium, interest, issuance costs, and any required rebate to the federal government, amounts in the state highway fund are available for appropriation by the legislature to make those payments.