Driving · Commercial
CDL General Knowledge Test
The written test every commercial driver takes for a CDL permit: inspection, vehicle control, safe driving, cargo and emergencies.
Questions last checked against the official sources on October 5, 2026.
The real exam at a glance
- Required for
- Every CDL class (A, B, C)
- Based on
- Your state's CDL manual
- Next
- Endorsements and skills test
- Age
- 21 for interstate, 18 intrastate
What you'll practise
Try a question
When following another vehicle at night, how should you use your headlights?
- Turn them off
- Flash them constantly
- Use high beams
- Use low beams
Show the answer
D. Use low beams — High beams can blind the driver ahead through their mirrors.
Sample questions by topic (in English)
- Licensing rules
- Vehicle inspection
- Basic control
- Speed and space management
- Seeing and hazards
- Emergencies and skids
- Cargo
Ask the examiner
Ask about this exam: why an answer is wrong, a grammar point, or “quiz me on …”.
Practice help only — no immigration, citizenship, legal or eligibility advice. For your application, ask the official authority. Answers can be wrong; check important facts. Chats aren't saved on our servers.
Questions about the CDL General Knowledge
Is this the official CDL General Knowledge?
No. Semplr is independent and not affiliated with the exam body. We write every question ourselves, in the official format and at the official level.
What is the real CDL General Knowledge like?
Required for: Every CDL class (A, B, C). Based on: Your state's CDL manual. Next: Endorsements and skills test. Age: 21 for interstate, 18 intrastate.
How is my practice marked?
Instantly. You see your score against the pass mark, and an explanation for every question — including the ones you got right.
Can I take it on my phone?
Yes. The whole mock exam works on a phone, and your progress is saved in your browser.
Ready for a full run?
One sitting, real timing, then your score against the pass mark.
Start the free mock exam