CDL Cheat Sheet: 20 High-Impact Questions
These are not leaked questions or a passing guarantee. They are high-priority, handbook-informed rules selected to give you a focused start before a full-length test.
Start now
Then complete the three Core Tests. Each uses the practice length recorded for your state; confirm the official format with your licensing agency.
What it includes
A focused entry point built from high-priority topics.
Three full-length tests that match your state exam length.
Diagnostic, adaptive practice, and mistake review are still available.
Use the Cheat Sheet for an efficient start, then continue to a full CDL practice test for complete preparation.
Sample CDL cheat sheet 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 · Our sources
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CDL Cheat Sheet FAQ
Does the Cheat Sheet replace a CDL practice test?
No. It is a focused start on priority rules. Follow it with the Core Tests or your full state practice test to rehearse the real question count.
How are Cheat Sheet questions selected?
They come from high-priority, handbook-informed topics, with a preference for your selected state's questions when available. They are not leaked questions or a passing guarantee.
What length do Core Tests use?
Each Core Test uses the practice length recorded for your state. Confirm the official format with your licensing agency.