DE CDL Combination Practice Test (2025)

1. If you get stuck on the railroad tracks, the first thing you should do is:

try to move your vehicle until you see the train.
immediately get out of the cab and move away from the tracks.
scream for help.
stay in your vehicle and call 911.

2. After coupling the trailer, begin raising the landing gear by using:

3. Blocking _______________ to keep it from sliding.

goes from the upper part of the cargo to the floor
is used in the front, back, and/or sides of a piece of cargo
is used only in the back of a piece of cargo
None of the above.

4. Empty trucks require _____ stopping distances because empty vehicles have ______ traction.

5. When backing a trailer, turn the wheel right to make the cab go ________ and the trailer go ________.

6. What is the proper following distance for a 50 foot truck traveling at 50 mph?

7. If your vehicle is equipped with air brakes, loss of air pressure in the emergency line causes:

the speed of your vehicle to increase.
the trailer spring brakes to come on.
the trailer emergency brakes to come on.
All of the above.

8. When checking your tires during a pre-trip inspection, which of the following is acceptable?

Dual tires that come in contact with parts of the vehicle
Mismatched sizes
Tires made by different manufacturers
Cracks in the tires

9. If the fifth-wheel locking lever is not locked after the jaws close around the kingpin:

the parking brakes are on and your vehicle is safe to drive.
the coupling is not right and you should not drive until you get it fixed.
the parking brakes are on and the wheels are chocked.
cargo is properly blocked.

10. Which of the following is NOT a step in backing up with a trailer?

Looking at your line of travel before you begin
Backing slowly
Checking the outside mirrors on both sides frequently
Backing quickly when the path is straight

CDL COMBINATION PRACTICE TEST (DE)