Colorado Department of Revenue, Division of Motor Vehicles
Colorado CDL practice tests
How Colorado handles the commercial learner permit, the fees and the skills test.
- General Knowledge24 questions, required of every applicant
- Air Brakes20 questions, skip it and an L restriction applies
- Combination Vehicles18 questions, needed for Class A
- Hazardous Materials20 questions, endorsement H
- Tank Vehicles16 questions, endorsement N
Every knowledge area
The 145 questions are the same in every state. Start with general knowledge, then sit the areas Colorado will write onto the permit.
General Knowledge
Required of every applicant: inspection, control, space and speed management, hazard perception, emergencies and hours of service.
Air Brakes
Air brake knowledge and vehicle checks for applicants who may drive vehicles with air brakes.
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.
What is different in Colorado
Colorado in particular
Colorado hands the entire skills test off to approved third party testers rather than offering it at its own driver license offices, so the state office visit only ever covers the written knowledge test and the final license issuance, never the driving portion itself.
The written exams themselves are federal
Colorado 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 Colorado commercial learner's permit must be held for 14 calendar days before the skills test can be taken at an approved third party testing facility, and the permit is valid for one year and cannot be renewed.
Colorado Department of Revenue, Division of Motor Vehicles, checked Aug 28, 2026Fees
A Colorado commercial driver license costs $35 and the commercial instruction permit costs $20.
Colorado Department of Revenue, Division of Motor Vehicles, checked Aug 28, 2026Where you test
The written CDL knowledge test is taken by appointment at a state driver license office, while the skills test is administered only through an approved third party testing facility.
Colorado Department of Revenue, Division of Motor Vehicles, checked Aug 28, 2026Colorado CDL written exams, in the federal format.
145 cited questions, free, with nothing to sign up for. The permit rules above are Colorado's. The knowledge is 49 CFR Part 383.