(a) Vehicle group descriptions. Each driver applicant must possess and be tested on his/her knowledge and skills, described in subpart G of this part, for the commercial motor vehicle group(s) for which he/she desires a CDL. The commercial motor vehicle groups are as follows:
Code of Federal Regulations207
(1) Combination vehicle (Group A)—Any combination of vehicles with a gross combination weight rating (GCWR) of 11,794 kilograms or more (26,001 pounds or more) provided the GVWR of the vehicle(s) being towed is in excess of 4,536 kilograms (10,000 pounds).
(2) Heavy Straight Vehicle (Group B)—Any single vehicle with a GVWR of 11,794 kilograms or more (26,001 pounds or more), or any such vehicle towing a vehicle not in excess of 4,536 kilograms (10,000 pounds) GVWR.
(3) Small Vehicle (Group C)—Any single vehicle, or combination of vehicles, that meets neither the definition of Group A nor that of Group B as contained in this section, but that either is designed to transport 16 or more passengers including the driver, or is used in the transportation of materials found to be hazardous for the purposes of the Hazardous Materials Transportation Act and which require the motor vehicle to be placarded under the Hazardous Materials Regulations (49 CFR part 172, subpart F).