Commercial Driver's License manuals vary by state, with the appropriate version typically available at one of the local driver's license issuing facilities or from the state's Department of Transportation website. There are three classifications of CDLs, and applicants must choose the appropriate study materials for each.
CDL classifications are available in A, B or C types, with various endorsements for specific equipment and cargo available for each. Endorsements may require additional written knowledge tests, and usually a skills test. The classification rating generally certifies a licensee for a specific gross weight range and type of cargo to be driven. Endorsements add specialized capabilities including transporting passengers, driving school buses, operating farm equipment, towing tankers or hauling hazardous material, which also requires fingerprinting and a background check.
Many states also offer downloadable practice tests for study, along with study guides. A knowledge exam must be taken in order to receive a learner's permit allowing the holder to drive with a CDL holder present. Most states require a medical certification, or DOT approved medical card, and proof of identification before a knowledge exam can be taken. The medical certification generally requires submission by an approved medical service provider, after a specified examination. Identification requirements typically include proof of citizenship, such as a birth certificate or valid U.S. Passport, as well as a verifiable Social Security number and residence.