Free Illinois CDL practice test with real commercial driving questions. Prepare for your Illinois CDL exam — General Knowledge, Air Brakes, HazMat, and all endorsements. Updated for 2026.
The Illinois Secretary of State knowledge exam tests your understanding of Illinois traffic laws, road signs, and safe driving practices. DriveAce covers every topic you'll encounter on test day.
Vehicle inspection, cargo management, driving techniques, and documentation.
Air brake system components, inspection, emergency stops, and maintenance.
Hazardous materials classification, placarding, loading/unloading rules.
Liquid surge, rollover prevention, loading and unloading procedures.
Coupling, uncoupling, stability, and safe driving with multiple trailers.
Passenger safety, school bus operations, railroad crossings, evacuation.
The Illinois CDL knowledge test has 50 questions for General Knowledge. You need 80% to pass. Each endorsement (Air Brakes, HazMat, Tanker, etc.) has an additional 20-30 questions.
DriveAce covers General Knowledge, Air Brakes, HazMat, Tanker, Doubles/Triples, Passenger, School Bus, and Combination Vehicle endorsements for Illinois.
Yes! DriveAce offers free CDL practice questions for Illinois. Study General Knowledge and endorsement-specific questions that mirror the real Illinois Secretary of State CDL exam.
You need to score 80% or higher on the Illinois CDL knowledge test and each endorsement test. DriveAce practice tests use the same passing threshold so you know when you're ready.
Join thousands of drivers who passed their test on the first try with DriveAce. No subscription. No ads. Just the knowledge you need.
Start Free Practice Test →$19.99 one-time for full access. 20 free questions included.