Guides
The practice tests check what you know. These explain it. Every figure names the handbook or the regulation it came from, the same as every answer on the site.
All guides
- CDL classes: A, B and C explained What Class A, B and C actually cover under 49 CFR 383.91, which knowledge tests each group needs, and how to work out which class your job calls for.
- CDL endorsements: which ones you need The six CDL endorsements: H, N, X, T, P and S. What vehicle or cargo triggers each one, which adds a background check, and the test you have to sit for it.
- How CDL knowledge tests are scored Every CDL knowledge test is passed at 80 percent under 49 CFR 383.135. What a restriction is, how failing air brakes creates one, and what a retake involves.
- The commercial learner's permit What a commercial learner's permit is, the test you pass to get one, the 14-day wait before a skills test under 49 CFR 383.25, and how long it lasts.
- The seven-step air brake check The seven tests in the final air brake check, what each one proves, and the psi figures that decide a pass, cited to the CDL manual's air brakes section.
- What is on the CDL general knowledge test The twenty subjects 49 CFR 383.111 puts on the CDL general knowledge test, which of them the handbook spends the most pages on, and where people lose marks.
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