Illinois CDL practice tests

Illinois is one of the few states that runs driver licensing, CDLs included, through the Secretary of State's office rather than a Department of Motor Vehicles. It's a quirk of how the state organized itself early on, and it means the agency you deal with for a commercial license is the same one that handles business filings and vehicle titles — not a dedicated motor vehicle department. Illinois is also a state of two very different geographies for this purpose: dense testing coverage around Chicago and the collar counties, and much wider gaps between offices once you're downstate.

What Illinois requires

Every figure below names the document it came from, so you can check it rather than take our word for it.

Passing score
80% 49 CFR Part 383, Commercial Driver's License Standards, 383.135
Minimum age (in-state driving)
18 years old 49 CFR Part 383, Commercial Driver's License Standards, 383.71
Minimum age (across state lines)
21 years old 49 CFR Part 391, Qualifications of Drivers, 391.11
Permit holding period
14 days 49 CFR Part 383, Commercial Driver's License Standards, 383.25

Fees change without notice, so we do not repeat them here. Check Illinois Secretary of State for the current cost.

Illinois practice tests

The knowledge tests are set by federal rule, so the questions are the same wherever you sit them. What changes is the paperwork above.

What Illinois does differently

The exam material itself doesn't change by state. 49 CFR Part 383 sets the knowledge tests, the endorsements and the 80 percent pass mark, and the Secretary of State's office administers the same format as any DMV would. The real difference in Illinois is administrative: because licensing sits inside a larger agency with many other functions, CDL testing is concentrated at specific facilities rather than every local office, so it's worth checking that a Secretary of State location actually offers commercial testing before assuming the nearest branch will do it.

Which tests you actually need

General knowledge is required of everyone. Beyond that, it's about the vehicle. Air brakes call for a separate exam, and failing it doesn't cost you the license — it adds a restriction against driving anything fitted with them. Combination vehicles come into play for trailers over 10,000 pounds. From there, the endorsements follow: tank, doubles and triples, passenger, school bus, hazardous materials.

Hazmat brings in a Transportation Security Administration background check alongside the written test, and that check runs on federal timing the state doesn't control. Given that CDL testing in Illinois is concentrated at fewer facilities, it pays to start that background check as soon as you know hazmat is part of your plan, rather than after you've already booked a slot.

Before you book

You need a commercial learner permit before the skills test, and federal rule sets how long it must be held before that test can happen. Sit the knowledge exams early in that period so a failed attempt still leaves room for a retake before the permit expires.

Fees don't appear on this page. Illinois sets and adjusts them, and an outdated number is worse than none, so confirm the current fee with the Secretary of State before you go. What this site gives you instead is the exam content itself, with each answer traced to its source. Whether you're testing near Chicago or well downstate, the material you're tested on doesn't change — only the drive to reach a facility that offers it does, so it pays to check that detail first.

Jump to a test

Every question on every one of these is free, and each answer names the handbook page it came from.

Other states

Cited to the page, every time.

Every question names the handbook, section and page it was read from, so you can check the answer instead of taking our word for it.

How we write these