District of Columbia Department of Motor Vehicles (DC DMV)
District of Columbia CDL practice tests
How District of Columbia 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 District of Columbia 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 District of Columbia
District of Columbia in particular
DC requires a 30 day hold on a commercial learner permit before the road skills test can even be scheduled, more than double the 14 day minimum used by several neighboring states, which stretches out the fastest possible route to a DC CDL.
The written exams themselves are federal
District of Columbia 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 DC DMV commercial learner permit must be held for at least 30 calendar days before the holder is allowed to schedule a CDL road skills test.
DC DMV, checked Aug 28, 2026Fees
$78 for the commercial driver learner permit, plus $117 for the first time or renewal commercial driver license itself
DC DMV, checked Aug 28, 2026Where you test
Knowledge tests are given at the DMV's Deanwood Road Test and CDL Services office, and road skills tests are conducted at DC DMV's own Commercial Driver Road Test Lot rather than through a private third party administrator.
DC DMV, checked Aug 28, 2026District of Columbia CDL written exams, in the federal format.
145 cited questions, free, with nothing to sign up for. The permit rules above are District of Columbia's. The knowledge is 49 CFR Part 383.