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Iowa CDL practice test

Getting a commercial driver's licence in Iowa starts with the CDL knowledge tests. The content is federal: every state, Iowa 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 Iowa driver licensing agency administers the test; the rules behind it are published by the FMCSA. Try the free Iowa CDL practice questions below, then pick a full test.

Free Iowa CDL practice questions

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

  1. If there are two left-turn lanes at an intersection, which one should you use?

    • The left-hand turn lane
    • Either one, it does not matter
    • The lane closest to the median
    • The right-hand turn lane
    Show answer
    Answer: D. The right-hand turn lane

    A large vehicle may need to swing right to make the turn. Starting from the right-hand turn lane keeps you from swinging into the vehicle beside you.

    Source: FMCSA CDL Manual, Section 2.7.5 (Space for Turns: Left Turns)

  2. When making a left turn, you should begin the turn:

    • When you reach the center of the intersection
    • As soon as you enter the intersection
    • Before you reach the intersection
    • Only after the light turns yellow
    Show answer
    Answer: A. When you reach the center of the intersection

    Turning too soon cuts the corner and puts the left side of the vehicle into the opposing lane or over the curb. Reach the center first, then make the turn.

    Source: FMCSA CDL Manual, Section 2.7.5 (Space for Turns: Left Turns)

  3. Because of your vehicle's size and weight, when crossing or entering traffic you should remember that:

    • Other drivers will always slow down for a truck
    • You need a larger gap because the vehicle takes longer to accelerate, especially when loaded
    • You can pull out into smaller gaps because the truck is heavy
    • You should accelerate hard to close the gap quickly
    Show answer
    Answer: B. You need a larger gap because the vehicle takes longer to accelerate, especially when loaded

    A heavy vehicle needs more time and room to get up to speed. Allow a bigger gap than a car would need, and do not count on other drivers to yield.

    Source: FMCSA CDL Manual, Section 2.7.6 (Space Needed to Cross or Enter Traffic)

  4. In the CDL manual, a 'hazard' is:

    • Only a crash that has already happened
    • Only a placarded hazardous materials load
    • Any road condition or other road user that is a possible danger
    • A traffic ticket for speeding
    Show answer
    Answer: C. Any road condition or other road user that is a possible danger

    Seeing hazards early, such as a car waiting to pull out or a work zone ahead, gives you time to plan a safe response instead of making an emergency move at the last second.

    Source: FMCSA CDL Manual, Section 2.8.1 (Importance of Seeing Hazards)

  5. Which of these is a clue that a parked car may be about to pull into your path?

    • Its windows are rolled up
    • It is parked on the right side of the street
    • It has out-of-state plates
    • Its brake lights or back-up lights are on, or exhaust is coming from the tailpipe
    Show answer
    Answer: D. Its brake lights or back-up lights are on, or exhaust is coming from the tailpipe

    A running engine, brake lights, or back-up lights show that someone is in the car and may move. Slow down or move over to give it room.

    Source: FMCSA CDL Manual, Section 2.8.2 (Road Users Who Are Hazards)

Every CDL test for Iowa drivers

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

How the Iowa 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 Iowa 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.

Iowa CDL test questions

How many questions are on the Iowa CDL test?

The Iowa 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 Iowa 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 Iowa?

At the Iowa 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 Iowa CDL practice questions?

Yes. Pick Iowa 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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