As used in this subchapter:
(1) “Other carriers” means all persons, firms, and corporations, other than rail carriers as defined in this section, which were subject to regulation by the former Arkansas Transportation Commission before the enactment of Acts 1945, No. 40, together with all persons, firms, and corporations that perform similar services in Arkansas.
(2) “Other carriers” includes common carriers by aircraft as defined under the Arkansas Air Commerce Act, § 23-14-101 et seq.; and
(3) “Rail carrier” means all persons, firms, and corporations engaged in the business of common carrier of freight and passengers by rail in Arkansas and which are subject to regulation by the Arkansas Department of Transportation.