Illinois General Knowledge Test
You'll face lake-effect snow on I-80 and grain trucks on I-57 — this test gets you ready for Illinois roads, not just the manual.
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Jump right in — 50 questions, 80% to pass. We'll track your progress so you know when you're ready for the Illinois DMV.
Key Topics
- •Pre-trip inspection & air brakes
- •Safe driving & cargo handling
- •Illinois-specific road rules
About the Illinois General Knowledge Test
Topics Covered
- ✓Vehicle inspection — Illinois examiners want every step of the pre-trip, especially for trucks hauling grain or livestock on rural routes.
- ✓Air brakes — mandatory for most Class A rigs in Illinois; you must know brake lag, emergency braking, and how freezing temps affect air systems.
- ✓Safe driving practices — includes managing speed on I-55's curves and stopping distances in lake-effect snow on I-80.
- + 3 more topics
📘 Study Tips & State Info
Illinois examiners don't mess around. They expect you to know the order of the pre-trip inspection cold — start at the front, work your way around, don't skip anything. They'll ask: 'What do you check on the steering axle?' Don't say 'tires.' Say 'tire condition, lug nuts, steering linkage, and suspension.'
Air brakes are a big deal here. Illinois has cold winters, so you'll get questions about moisture in air tanks, alcohol evaporators, and what happens when your brakes freeze. Know the difference between a dual air brake system and a single system. The manual has a table — learn it.
Practice with time pressure. The real test gives you 60 minutes for 50 questions. That's about 72 seconds per question. If you're spending 2 minutes on one, you're in trouble. Our practice tests time you the same way.
Illinois CDL testing is run by the Secretary of State's office. You'll need to bring your valid driver's license, Social Security card, proof of Illinois residency, and a valid Medical Examiner's Certificate (DOT card). Walk-ins are accepted at most locations, but appointments are strongly recommended — wait times can exceed 2 hours at Chicago-area facilities like the Chicago South location on W. 31st Street.
Testing fees: $60 for the written knowledge tests (General Knowledge plus any endorsements). That covers three attempts within one year. If you fail a test, you can retake it the next business day. No same-day retakes.
Illinois also requires a vision screening before you take the written test. If you wear glasses or contacts, bring them. The minimum visual acuity is 20/40 with or without correction. You'll also need to pass a basic sign recognition test — they show you road signs and you tell them what they mean.
About the Illinois General Knowledge Test
The Illinois General Knowledge test is your first step toward a Class A or B CDL. It covers everything from air brakes and pre-trip inspection to handling the unique conditions you'll face on Illinois highways. You need 40 out of 50 to pass — no exceptions.
Illinois isn't flat and boring. You've got lake-effect snow dumping on I-80 near Joliet, grain trucks crawling on I-57 downstate, and construction zones on I-55 that never seem to end. The test expects you to know how to handle those situations, not just recite federal rules.
You'll take this test at a Secretary of State facility. Most offices use computer-based testing. You can't bring your phone or notes. The questions come straight from the Illinois CDL Study Guide — so you better know it cold.
Don't waste time on memorizing tricks. Focus on understanding why you do what you do. That's what gets you past the Illinois DMV examiners and onto the road.
Topics Covered
Study Tips
Illinois examiners don't mess around. They expect you to know the order of the pre-trip inspection cold — start at the front, work your way around, don't skip anything. They'll ask: 'What do you check on the steering axle?' Don't say 'tires.' Say 'tire condition, lug nuts, steering linkage, and suspension.'
Air brakes are a big deal here. Illinois has cold winters, so you'll get questions about moisture in air tanks, alcohol evaporators, and what happens when your brakes freeze. Know the difference between a dual air brake system and a single system. The manual has a table — learn it.
Practice with time pressure. The real test gives you 60 minutes for 50 questions. That's about 72 seconds per question. If you're spending 2 minutes on one, you're in trouble. Our practice tests time you the same way.
Illinois Specific Information
Illinois CDL testing is run by the Secretary of State's office. You'll need to bring your valid driver's license, Social Security card, proof of Illinois residency, and a valid Medical Examiner's Certificate (DOT card). Walk-ins are accepted at most locations, but appointments are strongly recommended — wait times can exceed 2 hours at Chicago-area facilities like the Chicago South location on W. 31st Street.
Testing fees: $60 for the written knowledge tests (General Knowledge plus any endorsements). That covers three attempts within one year. If you fail a test, you can retake it the next business day. No same-day retakes.
Illinois also requires a vision screening before you take the written test. If you wear glasses or contacts, bring them. The minimum visual acuity is 20/40 with or without correction. You'll also need to pass a basic sign recognition test — they show you road signs and you tell them what they mean.