The provisions of §§18.41 through 18.45 apply only to merchandise to be exported under cover of a TIR carnet for the convenience of the U.S. exporter or other party in interest and do not apply to merchandise otherwise required to be transported in bond under the provisions of this chapter. Merchandise to be exported under cover of a TIR carnet for the convenience of the U.S. exporter or other party in interest may be transported with the use of the facilities of either bonded or non-bonded carriers.