A CDL Class A is for tractor-trailers or vehicles that weigh more than 26,000 pounds and have a trailer that weighs more than 10,000 pounds. Once you have a Class A CDL, you can also drive a Class B vehicle. One of the most popular vehicles you can drive with a Class A CDL is a tractor-trailer. Tractor-trailers (also called semi-trucks) are large vehicles used for transporting goods. Their containers don’t connect to the frame of the truck. These vehicles come with different types of trailers based on the goods they’re transporting. Types include dry van trailers, flatbed trailers, refrigerated trailers, Conestoga trailers, standard RGN trailers, lowboy trailers, and drop-deck/step-deck trailers With this license, you can also drive double and triple trailers and tractor-trailer buses. You will also be authorized to operate specialty vehicles like livestock carriers and tankers.