Big Rig Daily · Free Driver Tools

Free CDL Practice Test: General Knowledge

Check what you know before test day. Every question is based on a federal rule for commercial drivers, and each answer shows a one line explanation with a link to the rule. The test runs in your browser and nothing is saved.

Practice only. This is not an official test. Big Rig Daily wrote these practice questions from federal rules in 49 CFR Parts 383, 392, 393 and 395. Your state writes and gives the real CDL knowledge tests, so study your state CDL manual, which also covers state rules and topics not included here.

About this CDL practice test

The questions cover four parts of the federal rules that every commercial driver needs to know:

• Part 383, commercial driver's license standards, including the learner's permit, vehicle groups, disqualifications and the passing score.
• Part 392, driving of commercial motor vehicles, including alcohol, fatigue, phones, cargo checks, railroad crossings and warning devices.
• Part 393, parts and accessories, including tires, fire extinguishers, warning triangles and tiedowns.
• Part 395, hours of service, including the 11 hour, 14 hour and 30 minute break rules.

Every answer links to the rule on the official eCFR website, so you can read the exact wording. For a full list of what the general knowledge test covers and how to prepare, read the CDL general knowledge test study guide.

How to use your score

Federal rules require at least 80 percent correct to pass each CDL knowledge test. If you score below that here, read the explanation for each question you missed, then go back to the matching section of your state CDL manual. Take the test again a few days later to see what stuck.

The real test is written by your state and uses different questions, and it also covers topics this quiz does not, such as vehicle inspection steps, shifting, space management and night driving. Use this quiz as one part of your studying, not the only part.

Want to understand the hours rules in more depth? Try the free hours of service break calculator and the ELD and hours of service guide. For the full licensing process, see how to get a CDL step by step.

Frequently Asked Questions

Is this an official CDL test?

No. It is not an official test. Big Rig Daily wrote these practice questions from federal rules. Your state DMV or licensing agency writes and gives the real CDL knowledge tests, so study your state CDL manual.

What score do I need to pass the CDL general knowledge test?

Federal rule 49 CFR 383.135 requires at least 80 percent correct on each CDL knowledge test. On a 50 question test, that means at least 40 right answers.

How many questions are on this practice test?

There are 39 questions, each with three choices. You see the right answer, a short explanation and a link to the federal rule after every question, and your score at the end.

Does the practice test save my answers?

No. The test runs in your browser and nothing is sent or saved. Reloading the page starts a fresh test.