California CDL practice tests
California keeps CDL testing entirely in house rather than licensing private examiners: the skills test can only be booked by appointment at a dedicated Commercial Driving Test Office, a narrower set of locations than the state's regular DMV field offices used for the knowledge test.
The written exams themselves are federal. California decides the permit rules, the fees and who runs the skills test, but the knowledge you are tested on comes from 49 CFR Part 383 and is the same in every state, which is why the 145 questions here work wherever you apply.
What changes in this state
Commercial learner permit
A California commercial learner's permit must be held at least 14 days before the skills test, and it is valid for a maximum of 180 days, with one 180 day renewal allowed as long as the total stays within one year of the original application.
California Department of Motor Vehicles, checked 2026-08-28
Where you test
Knowledge tests are given at DMV offices during regular business hours, and skills tests are conducted only at DMV Commercial Driving Test Offices by appointment, with no third party testers involved.
California Department of Motor Vehicles, checked 2026-08-28
Every knowledge area
General Knowledge
Required of every applicant: inspection, control, space and speed management, hazard perception, emergencies and hours of service.
Air Brakes
Fail this and an L restriction bars you from any vehicle with air brakes, which is most of them.
Combination Vehicles
Coupling, the fifth wheel, off tracking and trailer swing. Needed for Class A.
Hazardous Materials
Placards, shipping papers, segregation and the security threat assessment.
Tank Vehicles
Liquid surge, baffles, outage and why a tanker rolls over so readily.
Doubles and Triples
Rearward amplification, converter dollies and coupling a second or third trailer.
Passenger Transport
Bus inspection, standee lines, passenger supervision and railroad crossings.
School Bus
Danger zones, loading and unloading, student crossing and evacuation.