Illinois CDL practice test
The CDL general knowledge test follows federal standards, so these questions apply in Illinois just as they do nationwide. Below the test you'll find the Illinois-specific steps to actually get licensed.
At speeds below 40 mph, what is the basic rule for safe following distance with a large vehicle?
Getting your CDL in Illinois
In Illinois, apply through the state licensing agency (IL DMV / DOT). The core steps are the same across states:
- Get a valid IL driver's license and provide required identity documents.
- Pass the DOT physical with a certified medical examiner and carry your medical card.
- Pass the written knowledge tests (general knowledge plus any endorsements you need).
- Hold your commercial learner's permit (CLP) for the required waiting period.
- Complete Entry-Level Driver Training (ELDT) with a registered provider, if required.
- Pass the skills test — pre-trip inspection, basic controls, and road test.
Exact fees, permit hold times, and document requirements are set by Illinois. Confirm the current details with the IL licensing agency before you go.
What is different in Illinois
Licensing in Illinois runs through the Illinois Secretary of State. The part that catches people out is not the test — it is the medical certificate, because the way it reaches the state changed in 2025.
Illinois handles CDLs through the Secretary of State, not a DMV. The Secretary of State’s own instruction is blunt: all medical certificates after 30 June 2025 must be submitted electronically by the medical examiner. What you still do in person is self-certify your medical category — every CDL holder self-certifies to renew or upgrade, and every commercial learner’s permit applicant self-certifies when they take the knowledge and skills tests.
Certifying intrastate puts a K restriction on your licence
If you self-certify as intrastate — either non-excepted (NA) or excepted (EA) — Illinois places a K restriction on the CDL or CLP. It says you may not operate a commercial vehicle in interstate commerce or across multiple states. It is not a penalty, but it is on the licence, and changing it means changing your self-certification.
Illinois moved to electronic medical certification on 30 June 2025. The Illinois DOT physical page has the rest — what the exam checks, what happens if your certification lapses, and the SOS contacts worth having.
Don't forget the DOT physical
A valid medical certificate is required before you can be licensed. Read our DOT physical guide to know what the exam checks and how to pass it the first time.