49 U.S.C. § 31132

1. (1)“commercial motor vehicle” means a self-propelled or towed vehicle used on the highways in interstate commerce to transport passengers or property, if the vehicle—
   1. (A)has a gross vehicle weight rating or gross vehicle weight of at least 10,001 pounds, whichever is greater;
   2. (B)is designed or used to transport more than 8 passengers (including the driver) for compensation;
   3. (C)is designed or used to transport more than 15 passengers, including the driver, and is not used to transport passengers for compensation; or
   4. (D)is used in transporting material found by the Secretary of Transportation to be hazardous under section 5103 of this title and transported in a quantity requiring placarding under regulations prescribed by the Secretary under section 5103.
2. (2)“employee” means an operator of a commercial motor vehicle (including an independent contractor when operating a commercial motor vehicle), a mechanic, a freight handler, or an individual not an employer, who—
   1. (A)directly affects commercial motor vehicle safety in the course of employment; and
   2. (B)is not an employee of the United States Government, a State, or a political subdivision of a State acting in the course of the employment by the Government, a State, or a political subdivision of a State.
3. (3)“employer”—
   1. (A)means a person engaged in a business affecting interstate commerce that owns or leases a commercial motor vehicle in connection with that business, or assigns an employee to operate it; but
   2. (B)does not include the Government, a State, or a political subdivision of a State.
4. (4)“interstate commerce” means trade, traffic, or transportation in the United States between a place in a State and—
   1. (A)a place outside that State (including a place outside the United States); or
   2. (B)another place in the same State through another State or through a place outside the United States.
5. (5)“intrastate commerce” means trade, traffic, or transportation in a State that is not interstate commerce.
6. (6)“medical examiner” means an individual licensed, certified, or registered in accordance with regulations issued by the Federal Motor Carrier Safety Administration as a medical examiner.
7. (7)“regulation” includes a standard or order.
8. (8)“State” means a State of the United States, the District of Columbia, and, in sections 31136 and 31140–31142 1 See References in Text note below. of this title, a political subdivision of a State.
9. (9)“State law” includes a law enacted by a political subdivision of a State.
10. (10)“State regulation” includes a regulation prescribed by a political subdivision of a State.
11. (11)“United States” means the States of the United States and the District of Columbia.