Illinois CDL practice test
Published Updated Licensing sources checked:
How do I prepare for the Illinois CDL knowledge test?
If you are preparing for your first permit, start with general knowledge and the official Illinois instructions below. If your vehicle needs air brakes or combination vehicles, add those federal study sets; for hazardous materials, use the separate hazmat set. Compare the state’s published test rules with its current manual before you test. These practice sets teach federal topics and do not copy the state exam.
This page is study material. It is not the Illinois state exam, and it does not copy state test questions. Check the official Illinois pages below before you test.
| Your situation | Start with… |
|---|---|
| A quick first try | Take a 10-question warm-up |
| Ready for a longer attempt | Take the 50-question general knowledge exam |
| Need state rules or documents | Check the Illinois application steps |
Illinois CDL study guide (PDF) — link checked . Study its rules alongside our federal-standard bank. Our 50-question exam length is a study setting; use the official counts below for Illinois.
The Illinois Secretary of State page opened October 29, 2026 says the general knowledge test has 30 standardized multiple-choice questions. The Illinois CDL study guide gives the question counts for the other written tests. Illinois rule 92 Ill. Adm. Code 1030.80 sets 80 percent for each classification and endorsement test and 90 percent for the separate school bus permit test. This site does not reprint those questions.
Which tests do I need in Illinois?
| Your vehicle or work | Required study and tests |
|---|---|
| All permit applicants | General knowledge. Official requirements. Federal warm-up · Federal exam mode |
| Class A combination vehicle | Add combination vehicles. Official requirements. Federal warm-up · Federal exam mode |
| Vehicle with air brakes | Add air brakes to avoid an air-brake restriction. Official requirements. Federal warm-up · Federal exam mode |
| Passenger vehicle | Add the passenger endorsement tests. Official requirements. Federal warm-up · Federal exam mode |
| School bus | Add the school bus endorsement and check the separate state permit rules. Official requirements. Federal warm-up · Federal exam mode |
| Charter bus or school bus permit | Check the separate state requirements; these are not covered by our bank. Official requirements. Read the state manual |
| Tank vehicle | Add the tank vehicle knowledge test. Official requirements. Federal warm-up · Federal exam mode |
| Hazardous materials | Add the hazmat knowledge test and state approval steps. Official requirements. Federal warm-up · Federal exam mode |
| Doubles or triples | Add the doubles and triples knowledge test. Official requirements. Federal warm-up · Federal exam mode |
Illinois has a separate school bus permit test. Its passing rule differs from the federal school bus endorsement. Our school bus study set does not simulate that separate permit test.
Before booking the exam, check Illinois CDL application steps and official fee lines.
| Test | Questions | To pass | Official source |
|---|---|---|---|
| General knowledge | 30 questions | 80 percent | State source |
| Combination, for Class A | 20 questions | 80 percent | State sourceState source |
| Air brakes | 25 questions | 80 percent | State sourceState source |
| Passenger | 20 questions | 80 percent | State sourceState source |
| Tank vehicle | 20 questions | 80 percent | State sourceState source |
| School bus endorsement (S) | 20 questions | 80 percent | State sourceState source |
| School bus permit (SBP) special test | Not more than 24 questions | 22 correct, or 90 percent | State sourceState source |
| Hazardous materials | 30 questions | 80 percent, after a TSA approval letter | State sourceState source |
| Doubles and triples | 20 questions | 80 percent | State sourceState source |
| Charter bus | 20 questions | 80 percent | State sourceState source |
Illinois language, permit and booking notes — checked 2026-10-29
Applicants must be at least 18 for intrastate driving and at least 21 for interstate commerce or passenger transport.
Knowledge tests are given in English on a computer that draws random questions. An audio format is available, and an in-person oral test requires a request after the audio attempt.
A commercial learner’s permit is valid for one year from the temporary card. The permit must be held at least 14 days before the skills and drive test.
The study guide says written knowledge tests are valid for a maximum of one year.
For unknown figures, check with the Illinois licensing agency. A blank count is not an estimate.
Federal study sets, not the Illinois exam
Use general knowledge, air brakes, combination vehicles, and hazmat to study the federal topics. Finishing one of those sets does not mean you passed the Illinois test.