A commercial driver’s license (CDL) is required to operate any vehicle used in commerce to transport passengers or property with a gross vehicle weight rating of 26,001 pounds or more, or a gross combination weight rating of 26,001 pounds or more with a towed unit that has a gross weight rating of 10,001 pounds or more.
In order to apply for a CDL in Utah, drivers must meet a number of standards, including:
Have held a valid Utah Class D driver’s license for at least one year.
Are at least 18 years old.
Are in possession of a Department of Transportation medical certificate
Classes of CDLs authorize the sorts of commercial vehicles and cargo that a holder may operate. Following are the fundamental CDL classes:
Class A: Permits operation of any combination of vehicles with a gross combined weight rating of 26,001 pounds or more if the gross vehicle weight rating of the vehicle or vehicles being towed is greater than 10,000 pounds.
Class B: Permits operation of any single vehicle with a gross vehicle weight rating of 26,001 pounds or more, or any single vehicle towing another vehicle with a gross vehicle weight rating of less than 10,000 pounds.
Class C: Allows a driver to operate a single vehicle with a gross vehicle weight rating of less than 26,001 pounds or any single vehicle towing another vehicle with a gross vehicle weight rating of less than 10,000 pounds, provided the vehicle is designed to carry 16 or more passengers (including the driver) or hazardous materials.
In addition to classes of CDLs, truck drivers may receive endorsements to their licenses that permit them to operate specific types of vehicles or transport specific categories of cargo that are not covered by the basic classes. Common CDL endorsements for truck drivers include the ability to operate double- and triple-trailer combinations.
Allows driving of any truck designed to transport liquid or gaseous products in a tank container

Authorizes the transport of dangerous materials
Tank vehicle and hazardous materials combination endorsements

Applicants for a CDL must pass one or more written knowledge exams, depending on the kind of CDL and endorsements being sought. In addition, applicants must complete a vehicle skills examination in which they must demonstrate the competence to examine and operate a commercial vehicle safely. In the last step, applicants must demonstrate their ability to operate a commercial vehicle safely in a variety of road circumstances.