All notes or bonds issued under the authority of Section 37-41-89 shall mature in approximately equal annual installments over a period of not exceeding six (6) years from the date of the issuance of such notes or bonds. Such notes or bonds may bear interest at a rate not exceeding that allowed in Section 75-17-105, and such interest may be payable annually or semiannually.
In the event the funds borrowed under the authority of Section 37-41-89 are to be expended for the purchase of used transportation equipment, then all notes or bonds evidencing such loans shall be made to mature within two (2) years from the date of the issuance of such notes or bonds.