Illinois CDL Practice Test 2026

Practice question bank

Sample questions

1. An Anti-Lock Braking System (ABS):

   • Cannot be used with air brakes.
   • Should be used on dry pavement.
   • Can assist in maintaining control when braking. ✓
   • Should only be used if all axles have ABS.

   Vehicle Equipment & Safe Operation · Answer: C · Official handbook: Texas Commercial Driver License Handbook (DL-7C), Section 2 – Driving Safely, p. 63

2. After an accident, flares should be used with caution because:

   • There may be spilled fuel on the ground that could ignite. ✓
   • Other drivers may not see the flares.
   • Flares are expensive.
   • Other drivers may get confused about what is happening.

   General Driving Knowledge · Answer: A · Official handbook: Texas Commercial Driver License Handbook (DL-7C), Section 2 – Driving Safely, p. 66

3. Why should a school bus stop a short distance from students who are waiting to board?

   • The students will have to walk to the bus, making it easier for the driver to watch their movements. ✓
   • The students will usually be waiting on a sidewalk.
   • The students may get scared of a school bus coming toward them.
   • Buses are difficult to drive.

   Sharing the Road · Answer: A · Official handbook: Texas Commercial Driver License Handbook (DL-7C), Section 10 – School Buses, p. 137

4. An air supply control in its "emergency" position will:

   • Turn on the air supply.
   • Apply the trailer emergency brakes. ✓
   • Prevent a skid.
   • Accelerate the vehicle.

   Bad Weather & Night Driving · Answer: B · Official handbook: Texas Commercial Driver License Handbook (DL-7C), Section 6 – Combination Vehicles, p. 95

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