CDL General Knowledge Practice Test

The General Knowledge test is the foundation of every CDL. Every commercial driver, regardless of vehicle class or endorsements, must pass it before adding any endorsements or class-specific tests. It covers the federal rules, road safety principles, and vehicle handling concepts that apply to all commercial motor vehicles, from straight trucks to tractor-trailers and buses.

This endorsement is part of our free CDL practice tests covering all classes and endorsements.

Requirements

Hold a valid non-CDL driver's license
Meet your state's CDL age minimum (18 for intrastate, 21 for interstate)
Pass a DOT medical exam and submit a current medical certificate (MEC)
Pass the General Knowledge knowledge test at your state DMV
Submit your CDL learner's permit application with required ID, residency, and Social Security documents
Complete Entry-Level Driver Training (ELDT) before taking the Class A or B skills test

What's on the Test

The General Knowledge test has 50 multiple-choice questions in most states (some states use a slightly different question count). You need an 80% score to pass. Topics include safe driving practices, transporting cargo safely, vehicle inspection procedures, communication with other drivers, speed and space management, hazard awareness, distracted-driving rules, fatigue and hours of service basics, accident procedures, and the consequences of alcohol and controlled substance use. The test draws from the General Knowledge section of your state's CDL manual.

Study Tips

Read the General Knowledge section of your state's CDL manual cover to cover, test questions are written directly from this material

Memorize the seven-step pre-trip inspection order and the most common defects to look for

Know the difference between controlled and uncontrolled braking, and when to use each

Study the rules on following distance: 1 second per 10 feet of vehicle length under 40 mph, plus 1 extra second at higher speeds

Understand the 'no zones', the four blind spots around a commercial vehicle where cars disappear from the driver's view

Pick your state to start

The General Knowledge test content is federal - but fees, ID rules, and test centers vary by state. Pick yours to get the right General Knowledge practice test and your state CDL handbook.

General Knowledge FAQ

Yes. The General Knowledge test is the gateway test for the CDL. You must pass it before you can take any endorsement tests (HazMat, Tanker, Passenger, School Bus, Doubles/Triples) or class-specific tests (Combination Vehicles for Class A). Once you pass General Knowledge, you receive a CDL learner's permit and can begin behind-the-wheel practice and additional knowledge tests.

Most states use 50 multiple-choice questions for the General Knowledge test, but a handful of states use slightly different counts. You need 80% to pass in every state. Check your state's CDL manual or our state-specific page for the exact number of questions in your state.

A few states allow CDL knowledge tests online, but most still require in-person testing at a DMV testing center to verify identity and prevent cheating. Check with your state DMV before assuming an online option is available.

The CDL General Knowledge test focuses on heavy commercial vehicles, their longer braking distances, blind spots, hours-of-service rules, cargo securement, and the federal regulations that apply to interstate commerce. The regular driver's license test covers passenger cars and basic road rules. Even experienced drivers find the CDL General Knowledge content significantly different and broader than the standard driver test.

Each state sets its own rules. If your CDL has been expired for a short period (typically under a year), most states allow a straightforward renewal without re-testing. If your CDL has been expired for several years, your state may require you to retake the General Knowledge test and possibly the skills test. Always check with your state DMV for current rules.

Other CDL Endorsements

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Passenger(P)

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School Bus(S)

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Doubles/Triples(T)

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