Illinois (IL) CDL Practice Tests

Use these five sample test questions to prepare for the Illnois Commercial Driver's License (CDL) permit.
 

Illinois CDL Practice Tests: General Knowledge, Combination Vehicle & Air Brakes

Drivers preparing for the Illinois Commercial Driver’s License (CDL) exam should focus on three primary practice tests. These align with the written knowledge exams required by the State of Illinois and help reinforce the material covered in the official CDL manual.

• General Knowledge CDL Practice Test
• Combination Vehicle CDL Practice Test
• Air Brakes CDL Practice Test

Using CDL practice tests alongside the state CDL manual can improve retention and increase confidence before taking the Illinois knowledge exams.

Preparing for the Illinois CDL Exam

Commercial driver licensing standards are established at the federal level by the Federal Motor Carrier Safety Administration (FMCSA). Each state, however, administers its own CDL testing and licensing process.

In Illinois, CDL licensing and testing are handled by the Illinois Secretary of State. The Secretary of State publishes the official CDL manual used for all written and skills testing:

• Illinois Commercial Driver’s License Manual (PDF)

The Illinois CDL manual applies to all commercial license classes, including:

• Class A CDL
• Class B CDL
• Class C CDL

Illinois CDL Eligibility Requirements

Age Requirements:
You must be at least 18 years old to operate a commercial motor vehicle within Illinois (intrastate).
You must be at least 21 years old to operate interstate or transport hazardous materials.

Valid Illinois Driver’s License

A valid Illinois non-commercial driver’s license is required before applying for a CDL.

Medical Certification

All Illinois CDL applicants must pass a DOT physical examination conducted by a certified medical examiner listed on the National Registry.

FMCSA medical certification requirements

CDL Knowledge Tests and Endorsements

Applicants must pass written knowledge tests covering general CDL topics, air brakes (if applicable), and any endorsements required for their intended type of driving.

Common CDL endorsements include:

• Hazardous Materials (H)
• Tank Vehicles (N)
• Passenger (P)
• School Bus (S)

Entry-Level Driver Training (ELDT)

Federal Entry-Level Driver Training (ELDT) requirements apply to many Illinois CDL applicants. ELDT includes classroom instruction and behind-the-wheel training completed through an FMCSA-registered provider.

ELDT is required for:

• First-time CDL applicants
• Drivers upgrading from Class B to Class A
• Applicants adding Hazardous Materials (H), Passenger (P), or School Bus (S) endorsements

FMCSA Training Provider Registry

Background Checks and Documentation

Certain endorsements, including Hazardous Materials, require a federal background check. Applicants must also provide documentation verifying identity, Illinois residency, and lawful U.S. presence.

Illinois CDL Application Process

CDL applications must be completed in person at an Illinois Secretary of State Driver Services facility.

View official Illinois CDL application steps

Illinois CDL Fees

CDL fees in Illinois are set by the Illinois Secretary of State and may vary based on license type, testing location, and endorsements.

• Commercial Learner’s Permit (CLP): Fees are typically charged at the time of testing and processing and may vary by facility
• New or Renewed CDL (Class A, B, or C): $60 (standard issuance fee)
• Reduced CDL Fee: $50 for drivers age 69 and older
• Skills Test: Additional testing fees may apply depending on the testing provider

Additional costs may apply for endorsement testing or background checks, such as fingerprinting for Hazardous Materials endorsements.

Confirm current Illinois CDL fees and requirements