- Updated for January 2025
- Based on 2025 IL commercial driver's license manual
Free Illinois CDL Combination Practice Test 2025
We’re glad you decided to take our free Illinois CDL Combination practice test! This practice test will help you prepare to pass the official CDL Combination Vehicles knowledge test. You should start by studying Section 6 (Combination Vehicles) of the official Illinois Commercial Driver’s License Study Guide (Illinois CDL Handbook 2025). Then by taking this practice test, you’ll absorb the relevant material and become more accustomed to being tested on it. The practice test is based on the official state CDL Study Guide, just like the official knowledge test. It’s up to date as of January, 2025 and has 30 multiple-choice questions. The questions and answers on this practice test will assess your understanding of such topics as combination braking systems, driving techniques, pre-trip inspections, and rollovers. However, this practice test differs from the official knowledge test in the extra features it provides to help you learn, including a hint and an explanation of the correct answer for each question, and an automated assistant for even more help.
There are three classes of Commercial Driver’s Licenses (CDLs): Class A, Class B, and Class C. A Class A CDL allows you to operate combination vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 or more pounds, provided the Gross Vehicle Weight Rating (GVWR) of the unit being towed is over 10,000 pounds. To drive semi-trucks and tractor-trailers, this is the class of CDL you want.
All aspiring commercial drivers must pass the General Knowledge written test. But to obtain a Class A CDL and drive semi-trucks or tractor-trailers, you must also pass the Combination Vehicles knowledge test. Otherwise, your CDL will include a restriction prohibiting you from operating tractor-trailers, which would defeat the purpose of obtaining a Class A CDL. In fact, if you don’t pass that knowledge test, you won’t even be allowed to practice driving tractor-trailers.
Once you obtain a CDL and all the endorsements you need, you can start earning money as a commercial driver. Illinois (especially the Joliet/Elwood area) has one of the greatest intermodal transportation hubs in the country, including extensive rail and highway networks and airports for air freight. Illinois is a leading agricultural producer of corn, soybeans, and livestock. In addition, Illinois is also a leading manufacturing state. Major manufacturing sectors include chemicals, machinery, and food products. Truck drivers transport all these and other products.
Major trucking routes include but are not limited to Interstates 55, 57, 80, 90, and 94; U.S. Routes 20, 30, and 51; and Illinois Route 53.
- Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements
- Triple-checked for accuracy
What you need to know
What to expect on the actual IL DMV exam
questions
correct answers to pass
passing score
List of questions (classic view)
- What is the proper following distance for a 90-foot vehicle traveling at 50 mph?
- You do NOT need to drive slowly to avoid a rollover on
- Which of the following is NOT part of stopping a trailer skid?
- What does the crack-the-whip effect cause?
- Since what year have trucks been required to have antilock brake systems (ABS)?
- What is the proper following distance for a 60-foot vehicle traveling at 30 mph?
- What percentage of truck driver deaths in crashes are the result of truck rollovers?
- Which of the following is NOT a step in backing your trailer?
- What is the first step in coupling a tractor-semitrailer?
- Which of the following is NOT true about an antilock braking system (ABS)?
- Which of the following makes a rollover more likely?
- Which of the following off-tracks the most?
- Which of the following is NOT a part of inspecting the fifth wheel?
- Which of the following is NOT a part of raising the landing gear?
- What will happen if air doesn't flow all the way to the back?
- Which of the following are likely to get stuck at a railroad crossing?
- Which of the following is NOT part of inspecting the sliding fifth wheel?
- Compared with a regular five-axle tractor-trailer, how much more likely is the final trailer of a triple to roll over?
- What is the usual range at which the trailer air supply knob will pop out?
- Which of the following is part of securing the tractor?
- Trucks built since 1975 usually have
- What should you do if your vehicle gets stuck at a railroad crossing?
- Which of the following is NOT part of a trailer air line system?
- Which of the following is NOT part of testing the trailer's service brakes?
- If you must back along a crooked path, which side should you back toward?
- Loss of air pressure in the emergency line causes
- Which of these statements is true?
- If you cannot make a right turn without swinging into another lane, what should you do?
- If there is a major leak in the _________, the tractor protection valve will close and the trailer emergency brakes will come on.
- The rear wheels of which vehicle will off-track the most?
More resources
- Alabama: Test 1 / Test 2
- Alaska: Test 1 / Test 2
- Arizona: Test 1 / Test 2
- Arkansas: Test 1 / Test 2
- California: Test 1 / Test 2
- Colorado: Test 1 / Test 2
- Connecticut: Test 1 / Test 2
- Delaware: Test 1 / Test 2
- District of Columbia: Test 1 / Test 2
- Florida: Test 1 / Test 2
- Georgia: Test 1 / Test 2
- Hawaii: Test 1 / Test 2
- Idaho: Test 1 / Test 2
- Illinois: Test 1 / Test 2
- Indiana: Test 1 / Test 2
- Iowa: Test 1 / Test 2
- Kansas: Test 1 / Test 2
- Kentucky: Test 1 / Test 2
- Louisiana: Test 1 / Test 2
- Maine: Test 1 / Test 2
- Maryland: Test 1 / Test 2
- Massachusetts: Test 1 / Test 2
- Michigan: Test 1 / Test 2
- Minnesota: Test 1 / Test 2
- Mississippi: Test 1 / Test 2
- Missouri: Test 1 / Test 2
- Montana: Test 1 / Test 2
- Nebraska: Test 1 / Test 2
- Nevada: Test 1 / Test 2
- New Hampshire: Test 1 / Test 2
- New Jersey: Test 1 / Test 2
- New Mexico: Test 1 / Test 2
- New York: Test 1 / Test 2
- North Carolina: Test 1 / Test 2
- North Dakota: Test 1 / Test 2
- Ohio: Test 1 / Test 2
- Oklahoma: Test 1 / Test 2
- Oregon: Test 1 / Test 2
- Pennsylvania: Test 1 / Test 2
- Rhode Island: Test 1 / Test 2
- South Carolina: Test 1 / Test 2
- South Dakota: Test 1 / Test 2
- Tennessee: Test 1 / Test 2
- Texas: Test 1 / Test 2
- Utah: Test 1 / Test 2
- Vermont: Test 1 / Test 2
- Virginia: Test 1 / Test 2
- Washington: Test 1 / Test 2
- West Virginia: Test 1 / Test 2
- Wisconsin: Test 1 / Test 2
- Wyoming: Test 1 / Test 2
Your go-to, trusted source
Experience the Driving-Tests differenceOur commitment to accuracy and quality in our practice tests
Explore our rigorous, multi-tiered verification process that ensures each question mirrors the official manual for unparalleled accuracy.
At Driving-Tests.org, we understand the importance of reliable and accurate practice tests to help you prepare for your DMV exam. That's why we've developed a meticulous process to create and continually update our practice questions, ensuring they reflect the most current driving laws and regulations.
Here's an inside look at how we maintain the highest quality in our practice tests.
Content Creation and Verification Process
- Alignment with Official Manuals:
Every question we develop is based on the most recent version of each state's official driving manual. Our team regularly monitors each state DMV's website for the latest updates to ensure our practice tests are always aligned with the most current information. - Community Feedback Integration:
We leverage feedback from our vast community of users to understand which topics are most frequently tested. This helps us focus on the areas that are most relevant and beneficial for your preparation. - Expert Content Creation:
Our in-house editor, Steven, who has extensive experience in driver education, crafts each question with precision. He conducts a thorough review of each question against the official manuals to ensure accuracy. - Rigorous Review Process:
Once Steven has finalized a set of questions, our team conducts a joint review session. This second level of scrutiny involves content accuracy, proofreading, and fact-checking to eliminate any errors. - User Feedback Mechanism:
After a question goes live on our site, we keep the lines of communication open. Each question features a feedback button, inviting users to report any issues or errors. This continuous feedback loop allows us to address and rectify any concerns promptly. - Responsive Updates:
In line with our commitment to accuracy, we quickly update our practice questions to reflect any changes in the DMV manuals. Additionally, we update the free electronic copy of the state's driver's license manuals on our site, typically within a few days after the DMV publishes them.
Our thorough quality control process ensures that you have access to practice tests that are as accurate and up-to-date as possible. We believe in the power of well-prepared drivers and are dedicated to providing you with the best study tools to help you succeed on your DMV exam.
Get your ELDT certificate and pass CDL exams the first time. Guaranteed.
Get full access to our 3-in-1 program, starting at $79. CDL schools charge $3,000-$4,000 for that.
All 1,500 IL exam-like questions
Pass Guarantee: pass your permit exam, or get your money back
ELDT certification included
Official FMCSA-approved provider, instant completion reporting
Industry-leading 99.06% success rate
Compare with the average US passing rate of 49%
Trusted by over 1.15 Million customers
The only program recommended by DMVs