About CDL Prep Hub
CDL Prep Hub is a free study resource for anyone preparing to sit a Commercial Driver's License knowledge exam in the United States. The site contains 526 practice questions covering all eight federally standardized CDL knowledge tests, every one with the correct answer marked and a written explanation that ties the answer back to the AAMVA Commercial Driver License Manual or the relevant federal regulation.
Why we built it
Becoming a professional commercial driver requires passing several knowledge exams plus a behind-the-wheel skills test. The official AAMVA model handbook is excellent, but many drivers learn best by doing — by reading the question and immediately seeing whether they got it right and why. CDL Prep Hub exists to fill that gap with the largest free, ad-supported question bank we could responsibly assemble. There is no signup, no paywall, and no quiz timer. You can read every page in curl if you want to.
How the question bank was assembled
The General Knowledge bank contains 228 questions sourced from a public dataset (General-Knowledge-CDL-test on GitHub) and adapted with explanations grounded in the AAMVA CDL Manual. The endorsement banks (Air Brakes, Combination Vehicles, Hazmat, Tanker, Doubles & Triples, Passenger, School Bus) were written from the corresponding chapters of the AAMVA Commercial Driver License Manual and from Title 49 of the Code of Federal Regulations. Together they amount to 526 unique multiple-choice questions across 8 subject areas.
Who we are
CDL Prep Hub is an independent project. We are not a state DMV, the Federal Motor Carrier Safety Administration, the American Association of Motor Vehicle Administrators, or any commercial trucking school. We do not issue licenses, schedule tests, or grade exams. We provide study material that mirrors the federal model, and we link out to the official agency in your state for everything else.
Our editorial standards
Every question on this site is checked against at least one authoritative source — the AAMVA CDL Manual, the FMCSA regulations, or a state CDL handbook — before publication. Where regulations have changed (for example, the air brake spring-engagement range has been quoted differently across handbooks over the years), we use the current AAMVA model wording. If you spot something incorrect, please use the contact page to let us know and we'll review it.
Disclaimer
The questions on CDL Prep Hub are for educational purposes only. They are representative of the federal AAMVA model exams but they are not the actual questions on your state's test. Always verify rules, weights, fees, and procedures with the licensing agency in your state before relying on them in the real world.