Commercial river's license training (or CDL training) is a specialized instructional program or course designed to prepare a student to obtain a commercial driver’s license (CDL). A CDL is required for a career as a truck driver. During training, students are taught the necessary knowledge and skills to successfully pass a series of tests to obtain their CDL. CDL training normally begins with classroom instruction geared towards passing the written exams for a CDL permit. The CDL permit is a learner's permit that allows a student truck driver to practice driving skills on public roads with a CDL licensed driver or instructor. A student graduates CDL training once he or she receives a CDL and proves that he or she can comfortably and safely drive and maneuver a truck. Most CDL training schools train drivers for a class A CDL, which allows the holder to drive a tractor trailer that weighs over 26,000 pounds.