A commercial motor vehicle (CMV) is an self-propelled or towed motor vehicle used on a highway in interstate commerce to transport passengers or property when the vehicle has a gross vehicle weight rating or gross combination weight rating, or gross vehicle weight or gross combination weight, of 10,001 pounds or more, whichever is greater; is designed or used to transport more than 8 passengers (including the driver) for compensation; is designed or used to transport more than 15 passengers, including the driver, and is not used to transport passengers for compensation; or is used in transporting hazardous materials.