Sources & Methodology

Where Koydo CDL's questions come from

Your CDL test is built from official federal and state material — so ours is too. Every question, rule, and number on Koydo CDL traces back to a named, public source. Here's exactly where, and how we keep it accurate.

Last reviewed: 2026-06-20

The official sources

FMCSA — Commercial Driver's License Program

The federal program that defines who needs a CDL, the license classes (A/B/C), and the endorsements. Our section structure follows it.

49 CFR Part 383 — Commercial Driver's License Standards

The federal regulation setting the knowledge and skills test requirements every state's CDL exam is built on.

FMCSA — Hazardous Materials Regulations

The rules behind the HazMat (H) endorsement test, including the TSA security threat assessment you complete before testing.

FMCSA — Hours of Service of Drivers

The 11-hour, 14-hour, 30-minute-break, and 34-hour-reset numbers that show up on the General Knowledge test.

U.S. Bureau of Labor Statistics — Heavy and Tractor-Trailer Truck Drivers

The official outlook and pay data we reference when we describe what a CDL is worth as a career.

Your state DMV / driver-license agency

Each state administers the actual test and sets its own fees, ages, and CLP wait. Every Koydo state guide links to the official source for that state.

How we review the content

Write from the rule, not the rumor. Each question starts from the FMCSA regulation or state DMV manual that the real test draws on — not from another study app.
Match the state.Fees, minimum age, and CLP wait come from each state's official DMV fields, and every state guide links to that source so you can verify it.
Editorial review. The Koydo Lyceum reviews questions and explanations for accuracy and clarity before they reach you.
Update on change. When the FMCSA or a state DMV changes a rule, we update the affected sections and state guides — and refresh the review date on this page.

Frequently asked questions

Where do Koydo CDL questions come from?

Every question is written by the Koydo Lyceum editorial team and checked against official material: the FMCSA Commercial Driver's License program, the federal standards in 49 CFR Part 383, and each state's own DMV manual. We don't scrape other apps — the source of truth is the same material your DMV builds its test from.

Are the numbers (fees, ages, CLP wait times) accurate for my state?

Each state guide is built from that state's official DMV fields — fees, minimum age, and commercial learner's permit (CLP) wait — and every state page links to the official DMV source so you can confirm it yourself. States change these, so if you spot a difference, the DMV is the authority and we update fast.

How often is the content reviewed?

We review the source set and methodology on a recurring basis; this page was last reviewed on 2026-06-20. When the FMCSA or a state DMV changes a rule, we update the affected sections and state guides rather than waiting for a yearly refresh.

Is Koydo CDL an official or government test?

No. Koydo CDL is an independent study aid. We are not affiliated with or endorsed by the FMCSA, any state DMV, or any official testing authority. Use Koydo to prepare; always confirm the current requirements with your state DMV before you test.

What if a Koydo answer disagrees with my DMV?

Your state DMV is always right. Email support@koydo.app with the question and your state and we'll correct it. Keeping the bank accurate is the whole point — a wrong answer that costs you a test day is a defect to us.

Independent study aid — not affiliated with or endorsed by the FMCSA, any state DMV, or any official testing authority. Always confirm official requirements with your state DMV.

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