Sources

Where our CDL facts come from

Every rule, fee and format on this site links to an official source. If a source is not official, we say so. Here is the full list.

Federal rules

The rules every state must follow. We read the regulation text itself.

49 CFR 383.135
The 80% passing score on each knowledge test.
49 CFR 383.91 and 383.93
License classes, endorsements and the tests each one needs.
49 CFR 383.25
Commercial learner's permit rules, including the 14-day wait.
49 CFR 392.10
Stopping at railroad crossings.
49 CFR 391.11
Driver qualifications, including age and the English requirement.

Pages from the agencies that run the programs.

FMCSA Training Provider Registry
Who needs entry-level driver training, and the February 7, 2022 start date.
TSA hazmat endorsement
The security threat assessment and fingerprints for the hazmat endorsement.
FMCSA National Registry of Certified Medical Examiners
Find a medical examiner for your DOT medical card.

Our questions are built from the national model CDL manual as published by states.

Minnesota CDL Manual (PDF)
State-published manual that contains the national model manual text. We use it to check numbers.
Massachusetts CDL Manual
A second state-published copy of the model manual, used for test formats.

Question counts and time limits are set by each state. We start from national defaults.

Crist CDL: Ohio test format
A third-party summary of test formats that we compare against the manuals.

Rules that are changing. We link the source for every claim.

Benesch: English language proficiency update
Timeline of the 2025 enforcement changes.
California DMV regulatory text
California's adopted emergency rule on English assessment before the skills test.

Numbers can differ by state and by manual edition. When you test, your own state's current manual is the final word.