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Free practice test · 300 original questionsFree practice · 300 questions

CDL General Knowledge Practice Test

This free CDL practice test covers the general knowledge exam every commercial driver takes first, written from the federal knowledge-test requirements in 49 CFR Part 383.

  • Multiple-choice knowledge test
  • 80% to pass (49 CFR 383.135)
  • item count set by your state
Start 20 free questions What’s inside
  • No signup to start
  • Every answer includes a source note
  • Updated November 1, 2026
CDL General Knowledge practice questions on a phone

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A real CDL General Knowledge question

Pick an answer. You will see whether you are right, why, and the source it comes from. No signup.

  • 20 free questions like this one
  • An explanation and a source note on every answer
  • No signup, no card
Safe drivingTry a real question

What is the "four-second rule" used for in CMV driving?

The real test at a glance

How many questions are on the CDL General Knowledge test, and what score passes?

Official format

80% to pass · question count set by your state

  • Variesquestions, set by the exam owner
  • 80%needed to pass
  • 300practice questions here, 20 free

Questions written from the federal CDL knowledge-test requirements in 49 CFR Part 383 and the required subject areas; not official state test questions. 80% is the federal threshold in 49 CFR 383.135. The regulation sets the percentage only — your state driver licensing agency sets how many questions the test has.

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CDL General Knowledge practice questions on a phone

Topic coverage

Topics covered in this bank

300 original questions, split by the topics the official source covers

Full topic blueprint and drills

From the question bank

Try 3 more real questions

Tap an answer to check it. Every explanation cites the official source.

  1. Q1Safe driving

    What should you do first when you notice your vehicle starting to skid on a wet road?

    Tap an answer to check it

  2. Q2Vehicle systems

    What does the air compressor do in a CMV air brake system?

    Tap an answer to check it

  3. Q3Cargo

    When must a truck driver recheck cargo securement during a trip?

    Tap an answer to check it

0 / 3 right · 3 to goKeep going: 20 free questions Read them all with answers

Study plan

How to pass the CDL General Knowledge

Learn the rules, drill until they’re automatic, then prove it in a timed mock test.

  1. Step 1

    Learn the pre-trip inspection in a fixed order so nothing is skipped under pressure

  2. Step 2

    Drill air brakes, combination vehicles, and space management — the highest-yield sections

  3. Step 3

    Know the disqualification and out-of-service rules, including alcohol and drug thresholds

  4. Step 4

    Review cargo securement, weight limits, and hazardous materials basics

  5. Test day

    Book the real test once you clear the pass mark comfortably, twice in a row.

Exam simulator

Sit a timed mock test for the CDL General Knowledge

  • A real countdown. One question at a time, no feedback until you submit.
  • Flag and review. Mark questions to come back to before you hand in.
  • Score by topic. Your result against the pass mark, every answer explained.

Topics are mixed across the whole bank, and a retake is a new draw.

Try the free mock test

The free mock test runs 20 questions from the free set, once. A full-length run is 50 questions. A practice mock test, not an official replica.

Free taster
20 q
Full run
50 q
Practice clock
50 min
Pass mark
80%

Start free

What you get free on the CDL General Knowledge

Free

$0

No account, no card

  • 20 original questions with source notes
  • Instant scoring
  • One free timed mock test (20 questions)
  • Free account adds saved progress + mistake review
Start free practiceRead the 20 free questions with answers →

Free study kit

Everything free for the CDL General Knowledge test

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Two box trailers heading down a divided highway toward hills at dusk

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CDL General Knowledge Test 2026: The 80% Rule, What It Covers, and the Numbers Drivers Miss

About these questions

How we check these questions

  1. Written from the source. Every question is our own wording of a fact in the Driving & Licenses source, never copied from a real exam.
  2. Checked against its section. Each answer names the section it comes from, and the answer is checked against that text. Anything we cannot confirm there is not published.
  3. Machine checks on the whole bank. Validators look for duplicates, missing explanations and missing sources.
  4. Re-checked on changes. When Driving & Licenses revises the source, the bank is audited again. Last update: November 1, 2026.

Questions written from the federal CDL knowledge-test requirements in 49 CFR Part 383 and the required subject areas; not official state test questions. Spot an error? Email [email protected] with the question; we check it against the source and fix confirmed errors. Editorial policy.

Tried the CDL General Knowledge questions?

Good to know

CDL General Knowledge FAQ

Federal rules set the 80% passing threshold but not a question count. Each state writes its own test — 50 questions is common for General Knowledge, so confirm with your state agency.

No. This bank covers General Knowledge. Air brakes, combination vehicles, tanker, and hazmat endorsements are separate state tests.

Yes. Open the exam simulator and sit a timed mock test of 20 questions built from the free questions, once, with no signup. At the end you see where you stand in each exam area, so you know what to study next.

The exam's agency publishes no topic weights, so it mixes topics in proportion to the question bank, favoring questions you missed before and never repeating one within a run. A retake is a new draw, so you will meet different questions. It is a practice mock test, not an official replica of the real exam.

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