A class B license is a specialized and hard-to-obtain license that allows drivers to operate vehicles that weigh over 26,000 pounds, as well as vehicles covered by a class C license. Vehicles that can be driven with this license include buses, farm labor vehicles and many trailers under 45 feet.
A driver with a class B license can drive any vehicles covered by a Class C license, which weigh under 26,000 pounds, as well as many vehicles that weigh over 26,000 pounds. However, a driver cannot tow trailers that weigh more than 10,000 pounds unless he has a class A license. A driver with a special Restricted Class B Fire Fighter License can also drive fire trucks. A driver who is transporting hazardous materials, pulling double or triple trailers/tanks, driving school buses, or using a vehicle that does not include an air brake requires a specialized class B license.
The class B license allows drivers to operate most commercial vehicles as long as they are not a combined tractor-trailer truck weighing over 26,000 pounds or they are not attached to a trailer weighing more than 10,000 pounds. For those specific vehicle and trailer combinations, the specialized class A license is required. A driver must already have class B and C licenses to qualify for the class A license.