Types of vehicles requiring a CDL include:
• Single vehicles with a GVWR (gross vehicle weight rating) of 26,001 lbs or more.
• Trailers with GVWR 10,001 lbs or more when combined with a towing vehicle to total 26,001 lbs or more.
• Vehicles designed to transport 16 or more persons (including driver), school buses, vehicles carrying hazardous materials.
License classifications, endorsements, and restrictions:
There are different classes (A, B, C) depending on vehicle type/size, passenger count, hazardous materials etc. Endorsements for things like double/triple trailers, tank vehicles, passenger transport, etc. Restrictions may also include things like no manual transmission, no air brakes, etc.
Out‑of‑Service Orders:
If a driver operates a commercial vehicle while under an out‑of‑service order, or with CDL suspended, revoked, or in disqualification, there are severe penalties.