A Commercial Driver's License (CDL) is required in the United States to operate any type of vehicle with a gross weight of 26,001 lb (11,793 kg) or over including (but not limited to) tow trucks, tractor trailers and buses. [1]

The Commercial Motor Vehicle Safety Act of 1986 was signed into law on October 27, 1986. The main purpose for the Act was to improve highway safety by making sure truck drivers and drivers of tractor trailers and buses have passed a written and driving test to become qualified to drive Commercial Motor Vehicles (CMVs), and to remove drivers that are unsafe and unqualified from the highways. The Act continued to give states the right to issue CDLs, but the national government established minimum requirements that must be met when issuing a CDL.