CDL Practice Test
1301+ real CDL questions covering all 50 states + DC, free forever. Take a full test, a 10-question diagnostic, or an adaptive mock right here — no signup, progress saved on this device.
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Standard driver's license knowledge test
Start Car / Permit →Commercial driver's license — FMCSA sourced
You're hereMotorcycle permit — MSF sourced
Start Motorcycle →What the CDL general knowledge test looks like
Pick your state in the test above and this page uses that state's configured format. Where a state publishes its own official count and passing score, the snapshot above shows it with the date we checked it; where it does not, these practice settings apply.
Practice modes on this page
Ten questions across the whole test. It ends with the topics costing you the most points.
Drills built from what you actually missed, not a fresh random set.
Every question you got wrong comes back until you get it right.
50 questions in your state's format, scored the way the real test is.
What "ready" means here
Readiness on this site is an estimate from your own practice on this device — how much of the material you have covered and how you scored on it. It is not a probability of passing, and we do not publish one: read how we would have to measure a pass rate before believing anyone else's. Readiness rises fastest by clearing weak topics, which is what the diagnostic exists to find.
Every CDL knowledge test
Each one is a separate exam with its own length and pass mark. Take only the ones your class and endorsements require — the process guide walks through which those are.
Start from your license class
CDL guides
Follow the guided CDL Study Path
Study the test in a clear order with 10 focused modules and topic-specific questions. Verified video lessons appear automatically as they are added.
Start the CDL Study PathIf you did not pass
Failing once is common and it is recoverable. Most states set a waiting period before a retake and some charge a retake fee — both are on your state's requirements page. Then come back here and run missed-question review before another full simulation: repeating the same test without fixing the topic repeats the same result.
Retake rules, fees and what to bring, by state. Your state's page below links to its own agency handbook.
Or jump straight to your state's page
Sample CDL general knowledge test questions
What is the maximum BAC allowed for CDL holders operating a commercial vehicle?
- A. 0.04%
- B. 0.08%
- C. 0.02%
- D. 0.00%
Show answer
A. 0.04% — CDL holders face a stricter 0.04% BAC limit because commercial vehicles are heavier and harder to stop, making impairment far more dangerous. Even at 0.04% a driver can be charged with DUI regardless of how they feel.
Universal rule · checked against 49 CFR § 392.5 — Alcohol prohibition and 0.04 BAC standard for drivers on duty · verified 2026-05-17
What are the three emergency equipment items required on commercial vehicles?
- A. Fire extinguisher, spare fuses, warning triangles
- B. First aid kit, flares, flashlight
- C. Jack, tire iron, jumper cables
- D. Tow strap, shovel, ice scraper
Show answer
A. Fire extinguisher, spare fuses, warning triangles — Federal law requires all commercial motor vehicles to carry a fire extinguisher of the correct type and rating, a set of three reflective warning triangles, and spare electrical fuses — missing any item is an out-of-service violation.
Universal rule · checked against 49 CFR § 393.95 — Emergency equipment on commercial motor vehicles · verified 2026-05-17
How often should you check your mirrors while driving a commercial vehicle?
- A. Every 30 seconds
- B. Every minute
- C. Every 5-8 seconds
- D. Only when changing lanes
Show answer
C. Every 5-8 seconds — Check mirrors every 5-8 seconds to maintain awareness of your surroundings and traffic conditions.
Universal rule · checked against FMCSA Commercial Driver License Manual — Section 2: Driving Safely · verified 2026-05-17
At what PSI does the low air pressure warning usually activate?
- A. 40 PSI
- B. 60 PSI
- C. 50 PSI
- D. 70 PSI
Show answer
B. 60 PSI — The low air pressure warning signal must come on before air pressure drops below 60 PSI.
Universal rule · checked against FMCSA Commercial Driver License Manual — Section 5: Air Brakes · verified 2026-05-17
Which of these is most important for safe driving?
- A. Proper cargo securement
- B. Having a radio
- C. Wearing sunglasses
- D. Having snacks
Show answer
A. Proper cargo securement — Proper cargo securement helps keep the vehicle stable and prevents cargo from shifting, falling, or creating a roadway hazard.
Universal rule · checked against FMCSA Commercial Driver License Manual — Section 3: Transporting Cargo Safely · verified 2026-05-17
Questions last verified 2026-05-17 · Reviewed by the DMV Prep editorial team · Editorial policy
Frequently asked questions
How many questions are on the CDL general knowledge test?
Practice settings vary by state. This site uses around 50 questions with a 80% study target; confirm the official format with your state agency.
Is this CDL practice test really free?
Yes. Every practice test on this page and everything in the DMV Prep app is free — no ads, no paywall, no account.
Where do the questions come from?
State driver handbooks and federal regulations are the reference base. Citation scope and recency are being revalidated across the bank.
Can I study in Spanish?
Yes — the DMV Prep app includes all 3,671+ questions in Spanish, and the whole app works in Spanish.
