CDL General Knowledge Practice Test
The CDL General Knowledge test is the foundation of every commercial driver's license — whether you're going for Class A, Class B, or Class C. Every state gives you a version of it, and passing it is required before you can add endorsements like Air Brakes, HazMat, or Passenger.
Our free CDL General Knowledge practice test pulls from public FMCSA regulations and the AAMVA model CDL manual that every state DMV uses as its source. Question stems and correct answers mirror what you'll see on the real knowledge test; explanations are written to help you understand why the right answer is right — so you can recognize the reasoning on test day instead of memorizing letters.
What this test covers
- Vehicle inspection basics and the seven-step method
- Basic vehicle control, backing, and turning
- Shifting gears and manual transmissions
- Seeing, communicating, and space management
- Distracted, aggressive, and drowsy driving
- Skid control, recovery, and adverse conditions
- Railroad crossings, mountain driving, and hazardous conditions
- Accident procedures, fires, and emergency equipment
How to study
- Start in practice mode so you get instant feedback and a written explanation after every question.
- Use missed-question review to re-drill only the items you got wrong.
- Switch to exam mode once you're scoring above 85% consistently — it simulates the real 50-question DMV test with an 80% pass line.
- Read the current General Knowledge chapter of your state CDL manual alongside the app.
Frequently asked questions
- How many questions are on the real CDL General Knowledge test?
- Most states give a 50-question multiple-choice General Knowledge exam and require 80% (40 out of 50) to pass. A few states ask more or fewer questions — check your state DMV.
- Is General Knowledge the same in every state?
- The core content is the same because it comes from federal (FMCSA) regulations and the AAMVA model manual. Wording and a handful of state-specific questions can vary.
Ready to start?
Practice this CDL topic free — no account needed for your first session. Unlock the full course when you're ready.