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Iowa CDL Practice Test

Free practice questions for the Iowa commercial driver license written exams — general knowledge, air brakes, combination vehicles, and every endorsement.

The Iowa DMV written test for driver licensing covers passenger vehicles, motorcycles, and commercial operations. All applicants must pass a 35-question knowledge test covering road signs, traffic laws, and safe driving practices to obtain a learner's instruction permit. Iowa's test is administered by the Department of Transportation Motor Vehicle Division and is available both online (for applicants under 18 near their 14th birthday) and in person at DMV offices. The test emphasizes practical driving knowledge relevant to Iowa's road conditions, including rural driving, farm equipment safety, and weather-related hazards. Applicants can study using the official Iowa Driver's Manual or the online practice test provided by the DOT.

About this section of the Iowa test

Iowa's commercial driver license (CDL) test includes a base knowledge test covering vehicle operation and safety, plus additional tests for each endorsement you need. Each endorsement (HazMat, Tanker, Passenger, School Bus, Doubles/Triples, Air Brakes) requires a separate 20-question knowledge test. All CDL applicants must complete entry-level driver training (ELDT). Passing scores and fees vary by endorsement type. The test covers commercial vehicle operation, hazardous materials regulations, passenger safety, and specialized equipment handling.

Start practicing

Open the Iowa practice test — pick car, motorcycle, or CDL, then drill quick quizzes or full simulated exams.

Read the source manual

Browse the official Iowa driver manual — every practice question deep-links to the page that explains the rule.

Frequently asked questions

How many questions are on the Iowa permit test?
The Iowa written permit test for cars has 35 multiple-choice questions. The motorcycle endorsement test has 25 questions, and CDL tests vary by endorsement (20 questions each for endorsements like HazMat, Tanker, or Passenger).
What's the passing score for the Iowa written test?
You must score 80% to pass. For the car test, that means answering at least 28 out of 35 questions correctly. For the motorcycle test, you need 20 out of 25 correct.
How much does the Iowa written knowledge test cost?
The knowledge test fee is $10. Additionally, the instruction permit fee is $6, and the driving skills test fee is $20. Total costs vary depending on which license type you're applying for.
How old do I have to be to take the Iowa permit test?
You must be at least 14 years old to take the permit test in Iowa. Applicants under 18 may be eligible for the online 'Skip the Trip' option if they are within 30 days of their 14th birthday.
Can I take the Iowa DMV test in Spanish or other languages?
Yes, Iowa offers the written test in multiple languages including Spanish. You must request your language preference when scheduling your appointment. An interpreter will be provided at no cost. Note: If you take the test in a non-English language, your license will have a restriction stating you may only drive with an interpreter present, and you'll still be required to read English traffic signs.
How many times can I retake the Iowa written test?
You have three attempts to pass the written test within a 90-day period. If you fail, you must wait at least one business day before retaking. If you fail three times or exceed 90 days without retaking, your application closes and you must restart the entire process.
Is the Iowa permit test online or in person?
Iowa offers both options. The 'Skip the Trip' online test is available for applicants under 18 who are within 30 days of their 14th birthday, using a computer (not phone or tablet) with an internet connection and parental supervision. Adults age 18 and older must take the test in person at a DMV office or county treasurer's office. After passing the online test, you still need to visit the office to receive your instruction permit.
What documents do I need to bring to the Iowa DMV?
Bring a primary form of identification (birth certificate or passport), proof of your Social Security number (Social Security card or W2), and two proofs of Iowa residency (utility bill or rental agreement). If you're under 18, bring your parent's or guardian's written consent (Form 430018). All documents must be original or certified copies and not expired. Iowa DOT has an interactive tool on its website to help you determine exactly which documents you need.

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