Official sources
This is the complete list. Every rule, figure and road sign in the CDL Practice Test app comes from one of
the 8 government publications below, and the app uses no other source.
We are not a government agency.
CDL Practice Test is an independent study app. It is not affiliated with, endorsed by or connected to the FMCSA,
AAMVA or any state driver licensing agency. We cannot issue a commercial learner's permit, a CDL or a test
appointment, and we do not process any official application — only your state agency can do that. A passing score
in this app means you met the federal 80% pass mark here, not an official result.
Each entry links to the publishing agency's own page. Some government servers refuse connections from outside the
United States or from anything that is not a desktop browser, so a link may fail to load on your network even though
the page is live; an archived copy is listed underneath for that case. The agency's own page is always the authority.
Federal regulations — the rules themselves
Published by the U.S. Government Publishing Office in the electronic Code of Federal Regulations. These are the
public-domain regulations the knowledge test is built on, and they are what each answer's explanation cites.
Commercial driver manuals — what the test covers
The manuals tell us which rules appear on the knowledge test and in what depth. They are the publishers' copyrighted
material and no text from them is reproduced in this app; every question is written from the regulation above.
Road signs
The shape, colour and code of every sign in the app come from the tables in the federal manual below, and the
artwork is that manual's own, which it places in the public domain.
Credit for each of the 84 sign files
The drawings are the federal manual's own and are public domain. The files themselves were downloaded from
Wikimedia Commons; each one is listed below with its MUTCD code, licence, author and the page it came from.
- D1-1a — Public domain, Federal Highway Administration - MUTCD · file page
- D5-1 — Public domain, Federal Highway Administration - MUTCD · file page
- D9-1 — Public domain, Federal Highway Administration - MUTCD · file page
- D9-2 — Public domain, Federal Highway Administration - MUTCD · file page
- D9-6 — Public domain, Ltljltlj ( talk · contribs ) · file page
- D9-7 — Public domain, Federal Highway Administration - MUTCD · file page
- D9-8 — Public domain, Federal Highway Administration - MUTCD · file page
- D9-9 — Public domain, Federal Highway Administration - MUTCD · file page
- I3-5 — Public domain, Federal Highway Administration - MUTCD · file page
- M4-9L — Public domain, Federal Highway Administration - MUTCD · file page
- R1-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R1-2 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R1-3P — Public domain, Federal Highway Administration - MUTCD · file page
- R1-6 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R10-11 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R10-11a — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R10-6 — Public domain, DelDot - State of Delaware · file page
- R15-1 — Public domain, author not stated on the file page · file page
- R15-8 — Public domain, DelDot - State of Delaware · file page
- R2-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R2-6P — Public domain, Federal Highway Administration - MUTCD · file page
- R3-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R3-2 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R3-4 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R3-5R — Public domain, author not stated on the file page · file page
- R3-7R — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R4-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R4-2 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R4-7 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R5-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R5-1a — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R5-3 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R5-6 — Public domain, author not stated on the file page · file page
- R6-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- R6-2R — Public domain, author not stated on the file page · file page
- R7-1 — Public domain, Federal Highway Administration - MUTCD · file page
- R7-8 — Public domain, DelDot - State of Delaware · file page
- R8-3 — Public domain, author not stated on the file page · file page
- R8-8 — Public domain, DelDot - State of Delaware · file page
- R9-3a — Public domain, Federal Highway Administration - MUTCD · file page
- S1-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- S4-3P — Public domain, Federal Highway Administration - MUTCD · file page
- S5-1 — Public domain, author not stated on the file page · file page
- W1-1R — Public domain, MUTCD_W1-1L.svg : derivative work: Fry1989 · file page
- W1-2R — Public domain, MUTCD_W1-2L.svg : derivative work: Fry1989 · file page
- W1-4R — Public domain, MUTCD_W1-4L.svg : derivative work: Fry1989 · file page
- W1-6 — Public domain, author not stated on the file page · file page
- W1-8 — Public domain, author not stated on the file page · file page
- W10-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W11-1 — Public domain, author not stated on the file page · file page
- W11-2 — Public domain, author not stated on the file page · file page
- W11-3 — Public domain, author not stated on the file page · file page
- W11-8 — Public domain, author not stated on the file page · file page
- W12-2 — Public domain, author not stated on the file page · file page
- W13-1P — Public domain, Federal Highway Administration · file page
- W14-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W14-2 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W14-3 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W16-7PL — Public domain, Federal Highway Administration - MUTCD · file page
- W16-9P — Public domain, Federal Highway Administration - MUTCD · file page
- W2-1 — Public domain, Federal Highway Administration - MUTCD · file page
- W2-2R — Public domain, author not stated on the file page · file page
- W20-1 — Public domain, author not stated on the file page · file page
- W20-4 — Public domain, Federal Highway Administration - MUTCD · file page
- W20-7 — Public domain, Federal Highway Administration - MUTCD · file page
- W20-7a — Public domain, Federal Highway Administration - MUTCD · file page
- W21-1a — Public domain, author not stated on the file page · file page
- W3-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W3-2 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W3-3 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W4-1R — Public domain, author not stated on the file page · file page
- W4-3 — Public domain, author not stated on the file page · file page
- W5-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W5-2 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W6-1 — Public domain, author not stated on the file page · file page
- W6-2 — Public domain, Federal Highway Administration - MUTCD · file page
- W6-3 — Public domain, Federal Highway Administration - MUTCD · file page
- W7-1 — Public domain, author not stated on the file page · file page
- W8-1 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W8-11 — Public domain, Federal Highway Administration - MUTCD · file page
- W8-2 — Public domain, Federal Highway Administration – United States Department of Transportation · file page
- W8-5 — Public domain, Federal Highway Administration · file page
- W8-9 — Public domain, Federal Highway Administration - MUTCD · file page
- W9-1 — Public domain, author not stated on the file page · file page
