Illinois CDL practice test

Getting a commercial driver's licence in Illinois starts with the CDL knowledge tests. The content is federal: every state, Illinois included, writes its tests from the FMCSA CDL manual, so the general knowledge test has 50 questions, the endorsement tests have 20 to 30, and the passing score is 80% on each. Illinois Secretary of State administers the test; the rules behind it are published by the FMCSA. Try the free Illinois CDL practice questions below, then pick a full test.

50general knowledge questions
80%passing score on every test
8knowledge tests covered
ILpick your state once in the app

Free Illinois CDL practice quiz

Five questions from the general knowledge, air brakes and combination vehicles banks, the three tests most Illinois Class A applicants take first. Tap an answer to see if you were right and read the explanation.

0 of 5 right0 of 5 answered

When the temperature drops, which part of the road freezes first?
Why is the road especially slippery right after it starts to rain?
If your vehicle starts to hydroplane, you should:
At night or in fog, your speed should allow you to:
When driving through a work zone, you should:

Every CDL test for Illinois drivers

Each page has a free ten-question quiz, the real question count, the 80% pass mark and what the test covers.

How the Illinois CDL knowledge test works

You take the general knowledge test first; it is required for every CDL class. Class A drivers add the combination vehicles test. Almost everyone takes the air brakes test, because skipping it puts an air brake restriction on the licence. Endorsements (hazmat, tanker, doubles/triples, passenger, school bus) each have their own knowledge test. Pass the tests and you hold a commercial learner's permit; the skills test in a truck comes later.

Fees, appointment rules and test centre locations are set by Illinois; the current ones from Illinois SOS are in the next section. What does not change is the content, and that is what PassRig drills.

Illinois CDL fees and rules

In Illinois the CDL is issued by the Illinois Secretary of State. The figures below are taken from its own pages and were last checked on 2 November 2026. Fees and rules change, so confirm with the agency before you go.

Study from the state's own book: Illinois CDL Study Guide. PassRig's questions are written from the same FMCSA manual it is based on.

What	IL	Source
Learner's permit fee	$50, original or renewal	ilsos.gov
CDL fee	Renewal or transfer from another state $60 ($50 at 69+); the original fee is not listed	ilsos.gov
Retest fee	No separate amount; after three fails of the same exam you pay the original fee again	ilsos.gov
Permit valid for	One year; a new permit after that means retaking all tests	ilsos.gov
Minimum age	18 within Illinois; 21 for interstate driving or carrying passengers	ilsos.gov
Appointment	Skills tests must be booked online or by phone; none stated for written tests	ilsos.gov
If you fail	None for the first two retakes; 30 days after three fails, 90 after six, a year after nine	ilsos.gov
Attempts allowed	Three per exam per fee paid	ilsos.gov
Test languages	English only, with an audio or oral option on request; a Spanish written test was announced in July 2024	ilsos.gov
Medical certificate	Everyone self-certifies in one of four categories; non-excepted interstate drivers keep a medical card on file	ilsos.gov
Entry-level driver training	Training from a registered provider before a skills test can be booked; hazmat training before the hazmat test	ilsos.gov
Also worth knowing	Pass mark 80%, school bus 90%; hold the permit 14 days before the skills test	ilsos.gov

4 official pages from Illinois SOS were read for this section. Nothing on it is estimated. The Illinois SOS site is not reachable from outside the US, so these were read from archived copies of its pages captured in 2026.

Illinois CDL test questions

How many questions are on the Illinois CDL test?

The Illinois CDL general knowledge test follows the federal model: 50 questions, 40 correct to pass. Endorsement tests are shorter: air brakes 25, hazmat 30, and combination vehicles, tanker, doubles/triples, passenger and school bus 20 each.

What is the passing score on the Illinois CDL permit test?

80% on every knowledge test, the same pass mark used across the United States.

Where do I take the CDL knowledge test in Illinois?

Illinois Secretary of State gives the test. Skills tests must be booked online or by phone; none stated for written tests The test content itself comes from the FMCSA CDL manual.

How much does a CDL permit cost in Illinois?

Illinois SOS lists the commercial learner's permit fee as $50, original or renewal. If you fail a knowledge test: None for the first two retakes; 30 days after three fails, 90 after six, a year after nine

Does PassRig have Illinois CDL practice questions?

Yes. Pick Illinois in the app and you get practice sets and mock exams built from the knowledge test content your state uses, with the real counts and the 80% line.