If you want to drive most commercial tractor trailers, you will need the class A Commercial Driver's License (CDL) for this. The exam ensures that commercial drivers are qualified and knowledgeable in their field while also meeting medical and safety standards.

The Commercial Driver’s License (CDL) test contains two parts: a written knowledge test and skills test. There are seven knowledge tests in total: one covers general knowledge, five cover specific endorsements, and an Air Brakes test. Each knowledge test is scored separately, and most drivers only take three or four.

All questions are multiple-choice with four answers. The skills test is performed in front of an examiner and divided into three parts: vehicle inspection test that tests your ability to decide if a truck is safe to drive; basic control skills test that tests your ability to park, turn, and back up the vehicle; and a road test that gauges your ability to safely drive the vehicle on the road. Every person wishing to obtain a Commercial Driver’s License must take and pass all three parts of the skills test.