IA · CDL Class B

Iowa Class B CDL Practice Questions

This Iowa Class B CDL practice page is tied to the 100-question bank saved for this run. It covers general commercial-driving knowledge, air brakes, hazardous materials, tank vehicles, passenger vehicles, and school buses, with topics such as inspection, braking, cargo, passenger safety, hazardous conditions, operating rules, and licensing responsibilities. The specialty modules are conditional rather than a list of tests every Class B applicant must take. Iowa applicants should match knowledge tests and endorsements to the vehicle, cargo, brake system, and work they plan to perform. First-time Class B applicants must also account for the commercial learner's permit process, the 14-day CLP holding period, applicable Entry-Level Driver Training, medical self-certification, and Iowa's pre-trip, basic-control, and road testing process.

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Every test draws only from the Iowa CDL Class B question bank.

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LICENSING GUIDE

What to know before you test

Use this overview together with the latest official guidance linked below.

Confirm that Iowa Class B matches the vehicle you will drive

Iowa defines Class B around a single commercial vehicle with a gross vehicle weight rating of at least 26,001 pounds, including such a vehicle towing another vehicle that is not rated above 10,000 pounds. Common examples include straight trucks, large buses, dump trucks, and school buses. A Class B CDL does not authorize a vehicle combination that requires Class A. This mixed practice bank also includes passenger, school-bus, tanker, hazardous-materials, and air-brake material for broader study, but those privileges depend on the actual vehicle and operation. Match the class, endorsements, and any restrictions to the work you expect to perform.

Prepare for the knowledge tests and Iowa CLP rules

Iowa requires the General Knowledge test for any CDL. For Class B, the Air Brake test applies when the vehicle uses air brakes. Passenger, School Bus, Hazardous Materials, and Tank knowledge tests apply when those endorsements or vehicle types are sought. Iowa publishes 50 questions for General Knowledge with up to 10 missed, 25 for Air Brake with up to 5 missed, 20 each for Passenger, School Bus, and Tank with up to 4 missed, and 30 for Hazmat with up to 6 missed. After required knowledge testing, a CLP permits supervised practice and must be held at least 14 days before skills testing.

Complete ELDT, medical steps, and endorsement-specific requirements

For a first Class B CDL, Iowa verifies applicable Entry-Level Driver Training before the skills test. ELDT also applies the first time a driver seeks the H, P, or S endorsement. A school-bus driver needs both Passenger and School Bus endorsements; Iowa describes separate knowledge requirements and representative-vehicle testing for those privileges. Applicants must also meet identity, residency, citizenship or lawful-presence, Social Security, and vision requirements. Commercial drivers self-certify their type of commerce, and drivers in categories that require medical qualification must keep the applicable medical certification current. These administrative requirements are separate from practice-test performance.

Use a representative Class B vehicle for Iowa skills and drive testing

After the CLP holding period and applicable ELDT are complete, Iowa requires the CDL skills and drive examination. The testing sequence includes a pre-trip vehicle inspection, basic vehicle-control or backing maneuvers, and an on-road driving test in a valid, registered, roadworthy vehicle representative of the class and endorsements sought. Passenger and school-bus endorsements require the corresponding representative vehicle and additional endorsement testing. Testing in equipment without the systems or configuration you need can result in CDL restrictions, so applicants should choose test equipment carefully. The questions on this page reinforce knowledge, but they do not replace supervised driving practice or Iowa's required skills examination.

REQUIREMENTS OVERVIEW

Iowa CDL Class B requirements

Requirements depend on the applicant and can change. Verify each item with the cited agency.

age

Iowa Class B CDL and CLP applicants

Iowa lists age 18 as the minimum age for a CDL. Iowa also notes that a driver must be at least 21 to operate a commercial motor vehicle in interstate travel.

documents

Applicants for an Iowa CDL or CLP

Iowa requires proof of full name, date of birth, Social Security number, citizenship or lawful presence, and Iowa residency, along with vision qualification. Commercial drivers must self-certify their type of commerce and meet applicable medical-certification requirements.

tests

Iowa Class B applicants

Iowa requires General Knowledge for Class B, with Air Brake testing when applicable. Passenger, School Bus, Hazmat, and Tank tests apply when those endorsements or operations are sought. After the CLP period and applicable ELDT, applicants complete pre-trip inspection, basic vehicle-control or backing maneuvers, and on-road driving tests in representative equipment.

passing

Iowa CDL knowledge-test applicants

Iowa publishes question and miss limits: General Knowledge 50/10, Air Brake 25/5, Passenger 20/4, School Bus 20/4, Tank 20/4, and Hazmat 30/6. Applicants take only the tests required for their class, vehicle, and endorsements.

applicability

Iowa Class B applicants using this mixed practice bank

This bank includes general knowledge, air brakes, hazardous materials, tank vehicles, passenger, and school-bus content. Those specialty modules are not all required for every Class B applicant. Passenger and school-bus operation require the appropriate endorsements, and Iowa requires both P and S to operate a qualifying school bus.

OFFICIAL REFERENCES

Sources for this guide

Open the current source before relying on licensing details.