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Colorado CDL practice test

Getting a commercial driver's licence in Colorado starts with the CDL knowledge tests. The content is federal: every state, Colorado included, writes its tests from the FMCSA CDL manual, so the general knowledge test has 50 questions, the endorsement tests have 20 to 30, and the passing score is 80% on each. The Colorado driver licensing agency administers the test; the rules behind it are published by the FMCSA. Try the free Colorado CDL practice questions below, then pick a full test.

Free Colorado CDL practice questions

Five questions from the general knowledge, air brakes and combination vehicles banks, the three tests most Colorado Class A applicants take first. Show the answer to read the explanation.

  1. What is the minimum tread depth for tires other than the front (steering) tires?

    • 4/32 inch
    • 1/32 inch
    • 8/32 inch
    • 2/32 inch
    Show answer
    Answer: D. 2/32 inch

    Front tires need at least 4/32 inch of tread in every major groove. All other tires need at least 2/32 inch. Worn tread cannot push water aside and loses grip.

    Source: FMCSA CDL Manual, Section 2.1.2 (Tires)

  2. Which of these tire conditions is a defect you must not drive with?

    • Radial and bias-ply tires used together on the vehicle
    • Tread depth of 5/32 inch on a steering tire
    • Two tires of the same size on a dual assembly
    • Valve caps in place on every tire
    Show answer
    Answer: A. Radial and bias-ply tires used together on the vehicle

    Mixing radial and bias-ply tires makes the vehicle handle unpredictably. Mismatched sizes, duals that touch each other, cuts, and recapped tires on the front of a bus are also tire defects listed in the manual.

    Source: FMCSA CDL Manual, Section 2.1.2 (Tire Problems)

  3. Rust trails or shiny metal around the wheel lug nuts most likely mean:

    • The wheel was recently washed
    • The tire is over-inflated
    • The brake drum is overheating
    • The nuts are loose
    Show answer
    Answer: D. The nuts are loose

    A loose nut lets the wheel move slightly against it, which scrapes away paint and leaves rust streaks. Check tightness of any nut that shows these signs before driving.

    Source: FMCSA CDL Manual, Section 2.1.2 (Wheel and Rim Problems)

  4. A crack in a brake drum is a defect when it is longer than:

    • One half the width of the friction area
    • One inch in any direction
    • One quarter of the drum diameter
    • Any crack at all, even a hairline
    Show answer
    Answer: A. One half the width of the friction area

    The manual says cracked drums are a defect when the crack is longer than half the width of the friction area. A cracked drum can break apart under braking heat and pressure.

    Source: FMCSA CDL Manual, Section 2.1.2 (Brakes)

  5. Brake shoes and pads are dangerously thin when the lining is less than:

    • 1/2 inch
    • 1 inch
    • 1/4 inch
    • 1/8 inch
    Show answer
    Answer: C. 1/4 inch

    Lining thinner than about a quarter inch is a defect. Also look for linings soaked with oil or grease, missing or broken shoes, and cracked drums.

    Source: FMCSA CDL Manual, Section 2.1.2 (Brakes)

Every CDL test for Colorado drivers

Each page has ten free sample questions, the real question count, the 80% pass mark and what the test covers.

How the Colorado CDL knowledge test works

You take the general knowledge test first; it is required for every CDL class. Class A drivers add the combination vehicles test. Almost everyone takes the air brakes test, because skipping it puts an air brake restriction on the licence. Endorsements (hazmat, tanker, doubles/triples, passenger, school bus) each have their own knowledge test. Pass the tests and you hold a commercial learner's permit; the skills test in a truck comes later.

Fees, appointment rules and test centre locations are set by Colorado and change over time, so check the state driver licensing agency before you go. What does not change is the content, and that is what PassRig drills.

Colorado CDL test questions

How many questions are on the Colorado CDL test?

The Colorado CDL general knowledge test follows the federal model: 50 questions, 40 correct to pass. Endorsement tests are shorter: air brakes 25, hazmat 30, and combination vehicles, tanker, doubles/triples, passenger and school bus 20 each.

What is the passing score on the Colorado CDL permit test?

80% on every knowledge test, the same pass mark used across the United States.

Where do I take the CDL knowledge test in Colorado?

At the Colorado state driver licensing agency (the DMV, DOT or equivalent). Check its website for locations, appointments and current fees; the test content itself comes from the FMCSA CDL manual.

Does PassRig have Colorado CDL practice questions?

Yes. Pick Colorado in the app and you get practice sets and mock exams built from the knowledge test content your state uses, with the real counts and the 80% line.

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