What do truck drivers have to do to get their trucking license?

A person wishing to obtain a Commercial Drivers License (CDL) must pass several tests.

A written test on highway safety, similar to a regular drivers test, this usually includes other things as well, like air brakes and stopping distances.

A written test on daily vehicle inspections. There are over 100 different parts of a truck a driver is supposed to inspect every day.

A driving maneuvers test, including (but not limited to) straight line backing, Sight Side "alley" docking (aka 45 degree angle docking) and general maneuvering through a course of left and right turns.

The road test. This generally includes driving several blocks, making left and right turns, and entering / exiting express ways. Bumping the curb at any time will immediately fail the test.

Other written tests are required for special endorsements, such as HazMat (Hazardous Materials) Tanker, or double/triple trailers.

And lets not forget the invasive Physical Examination, which must be renewed every 6 months to 2 years, depending on what the Doctor finds.