Illinois CDL Practice Test 2026

To obtain a Commercial Driver's License in Illinois, you must first pass the CDL general knowledge written test administered by the Secretary of State. The general knowledge exam consists of 30 multiple-choice questions covering vehicle inspection, basic control, safe driving, transporting cargo, and federal regulations. A score of 80% or higher (24 correct) is required to pass.

CDL Classes and Endorsements

Illinois issues three CDL classes. Class A covers combination vehicles over 26,001 lbs GVWR when the towed unit exceeds 10,000 lbs — this is what you need for tractor-trailers and most heavy hauling. Class B covers single vehicles over 26,001 lbs such as straight trucks, large buses, and dump trucks. Class C covers vehicles designed for 16+ passengers or those carrying hazardous materials that don't meet Class A or B criteria.

Beyond the general knowledge test, you may need additional written tests for endorsements: Hazardous Materials (H), Tanker (N), Passenger (P), School Bus (S), Doubles/Triples (T), or the combined HazMat-Tanker (X). Each endorsement requires its own written exam, and HazMat also requires a TSA background check.

Entry-Level Driver Training (ELDT)

Since February 2022, federal law requires Entry-Level Driver Training (ELDT) through an FMCSA-registered training provider before you can take the CDL skills test for a Class A or B CDL. ELDT is also required before adding Hazardous Materials, Passenger, or School Bus endorsements. This applies in Illinois and every other state.

Where to Take the Test

The CDL knowledge test is taken at any Illinois Secretary of State Driver Services facility. Walk-ins are typically accepted, though scheduling ahead is recommended. The test is available in English, Spanish, Polish, Chinese, and 6 other languages. Results are delivered immediately — pass/fail displayed on screen.

Preparing for Your CDL Test

The CDL test draws from the Illinois CDL Manual and the federal Motor Carrier Safety Regulations. Key topics include pre-trip vehicle inspection procedures, air brake systems, coupling and uncoupling, cargo securement, hours-of-service rules, hazard perception, and accident procedures. Illinois-specific regulations on weight limits, required permits, and designated truck routes may also appear.

Taking practice tests before your appointment is one of the most effective ways to prepare. Focus on understanding road signs and the concepts behind each question rather than memorizing answers — the real test may phrase questions differently than what you studied.

Retake Policy

Can retake same day if appointments available, otherwise wait 1 day. Up to 3 attempts per year. Must pay fee again after 3 failures.