CDL Testing

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CDL Knowledge Test

The first step to getting your CDL is to pass the knowledge test(s) required for the type of commercial vehicle you want to operate.

You can study for the knowledge test with the:

Types of CDL knowledge tests (number of questions/allowed to miss)

  • General knowledge for any CDL (50/10)
  • Combination vehicle for Class A (20/04)
  • Air brake (25/05)
  • Passenger (20/04)
  • School bus (20/04)
  • Doubles/Triples (20/04)
  • Hazmat (30/06)
  • Tank (20/04)
  • Iowa operator (if applicable) (25/5)

Where can I take the CDL knowledge test?

You can take your CDL knowledge test(s) at any of the following locations:

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CDL Skills and Drive Test

After you’ve held the commercial learner's permit (CLP) for at least 14 days and completed the Entry-Level Driver Training (ELDT), the next step is to pass the required skills and drive test. You must provide a vehicle that has a valid registration, is in good working order, and is representative of the class of license you are applying for.

Where can I take the CDL Skills and Drive test?

You can take your CDL Skills and Drive test(s) at any of the following locations:

About the Test

There are three phases of the drive test:

  1. Pre-trip vehicle inspection test.

    A pre-trip vehicle inspection test is required to show the vehicle is safe to drive. You will have to walk around the vehicle and point to or touch each item and explain to the license examiner what you are checking and why.

    You must successfully demonstrate all components of the airbrake check before you start the pre-trip vehicle inspection test – prepare for this by reviewing the information in section 11 of the CDL Manual .

    If you do not pass the airbrake check and/or the pre-trip vehicle inspection test, you must make another appointment to retake the test – that could be two or three weeks out, which will delay the issuance of your CDL.

    View the pre-trip inspection memory aid you can use during the test.

    You can also study for the pre-trip inspection test using the CDL test app. The app has videos and exam-like questions designed to assist you in successfully preparing for the pre-trip vehicle inspection test.

  2. Skills test (maneuvers around cones and backing maneuvers).

    See section 12 in the Commercial Driver License manual for a description of the skills test exercises and scoring.

  3. Driving test (on public roads with examiner).

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Study Resources

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CDL Test App

Iowa CDL Test App

Pass your Iowa CDL test on the first try with the Iowa CDL test app! Get 600+ exam-like questions, lifetime CDL Manual access, and expert tips — covering everything from pre-licensing to specialized endorsements.

Iowa app users: Register and activate your account to unlock the free app. One-time setup requires your name, email, password, birthdate, and last four digits of your driver’s license.

Apple  |  Android  |  Web-based test

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