A commercial driver's license is required to drive certain types of vehicles.
A class B license is required for vehicles with a gross vehicle weight of 26,000 lbs or more. A class A license is required for vehicles towing a trailer with *combined* gross vehicle weights of 26,000 lbs or more AND the trailer has a gross vehicle weight of 10,000 lbs or more.
A Commercial driver's license is also required to transport hazardous materials requiring placards or vehicles that carry 16 or more passengers. To drive a vehicle with air brakes, the license must be unrestricted. If the air brake knowledge test isn't taken when applying for the license, there will be an airbrake restriction on the license.
A class C license is a vehicle which requires a CDL but doesn't meet the requirements of a class A or class B license (eg, a bus with a gvw less than 26,000 lbs).
Other optional endorsements to a commercial drivers license are tanker vehicles, double/triple combinations trailers and hazmat endorsements. These endorsements just require successfully passing the knowledge test. A hazmat endorsement also requires a completing a background check and paying a hazmat fee.
Minnesota recently updated its CDL license laws to include some restrictions based on the vehicle you test with:
Automatic transmission restriction: Taking the test in a vehicle with an automatic transmission will restrict the CDL license to automatic transmissions only.
Tractor-Trailer restriction: Taking a class A test in a vehicle other than a tractor/trailer will not permit the license holder to drive a tractor-trailer. They may still operate fifth wheel, pintle and standard trailers.
Applying for a commercial driver's license consists of:
-Applying for and passing the required knowledge tests which gives you a 6 month permit. This requires a DOT medical certificate - it can be obtained from most clinics, usually from the occupational health department. You will also need to have a birth certificate or passport with you.
-Practicing driving with the permit which requires a licensed commercial vehicle operator to be in the vehicle.
-Scheduling and passing the skills exam which is split into two parts: The pre-trip inspection and the road test.
-Applying for the upgraded license.