In this subtitle the following words have the meanings indicated. “Commercial motor vehicle” means any motor vehicle used or maintained for the transportation of persons or property that: has 2 axles and an operating or registered gross vehicle weight that exceeds 26,000 pounds; has 3 or more axles; or is used in combination with another vehicle and has an operating or registered gross combined weight that exceeds 26,000 pounds. “Commercial motor vehicle” does not include: a privately owned antique truck that: is registered as a historic motor vehicle under § 13–936 of the Transportation Article; and displays appropriate registration plates that the Motor Vehicle Administration issues; a commercial motor vehicle that is operated: by a state or a subdivision of a state; by the United States; by a joint unit of: this State and the United States and other states; or this State and another state; by or for a state, political subdivision of a state, or private school as a school bus; by a volunteer or paid fire department or rescue squad as fire or rescue equipment; by a licensed vehicle dealer during a road test for sale, if the vehicle displays dealer registration plates that the Motor Vehicle Administration issues; or by a person as a privately owned bus used only in the transportation system of a county, municipal corporation, special taxing district, or other political subdivision to transport the public on a regular schedule between fixed termini as those terms are defined in the Transportation Article; a multipurpose passenger vehicle as defined in § 11–136.2 of the Transportation Article; a multipurpose passenger vehicle or truck that does not exceed 3/4 ton capacity when towing: a camping trailer as defined in § 11–106 of the Transportation Article; or a travel trailer as defined in § 11–170 of the Transportation Article; or a farm truck as defined in § 13–921 of the Transportation Article or a farm area motor vehicle as defined in § 13–935 of the Transportation Article that has 2 axles and a registered or operating gross or combination weight of less than 40,001 pounds. “Motor carrier” means a person who operates or causes the operation of a commercial motor vehicle on a highway in this State. “Motor carrier” includes: a lessor of a commercial motor vehicle who provides or buys the motor fuel used to operate the vehicle or pays for it as a part of rental or other costs; and a lessee whose lease entitles the lessee to receive a credit or refund for motor fuel that the lessor buys.