Topics on a test for a commercial driver's license permit may include how to properly shift a vehicle, how to inspect a vehicle, and how to handle adverse weather and emergencies. Each state develops and administers its own tests, so the exact questions and topics vary.
Other common topics on these tests include braking techniques, accident response, driving in the dark and avoiding dangerous situations. The test for a CDL permit is a written test only and does not require any driving.
Each state's Department of Motor Vehicles provides a manual for commercial drivers that covers material in the test; the manuals may include practice tests. Some states, such as Washington and California, also provide practice tests on their websites that can help drivers prepare for the exam. These sites may also offer online versions of the manuals. California offers practice tests in Spanish and American Sign Language. DMV.org provides a short free practice test on its website and sells longer tests.
All states require a CDL permit for individuals training to drive commercial vehicles, such as buses, trucks and limousines. In most states, individuals must already have a driver's license and be at least 18 years old in order to be eligible for a CDL permit.