FREE DC CDL Combination Test (2024)

1. When driving on slippery surfaces, you should:

make turns as quickly as possible.
not pass slower vehicles unless necessary.
change lanes often.
All of the above.

2. If a trailer does not have spring brakes, to keep the trailer from moving you should:

3. Tests have shown that trucks with a high center of gravity:

are less likely to roll over when entering a curve.
can roll over if the driver exceeds the posted speed limit for a curve.
can roll over if the driver slows down before entering a curve.
can roll over at the posted speed limit for a curve.

4. You are driving a combination vehicle and must use your brakes to avoid a crash. You should:

push the brake pedal as hard as you can and hold it there.
use stab braking or controlled braking.
use the parking brake.
brake lightly and hold the steering wheel firmly.

5. To prevent a rollover, the driver should:

drive on the shoulder if possible.
pay extra attention to the coolant level.
drive slowly around corners, on ramps, and off ramps.
make quick lane changes if possible.

6. You should always try to back toward the driver's side because:

you can watch the rear of your vehicle out the side window.
you can more easily correct any steering errors.
backing toward the left side is more dangerous.
None of the above.

7. To be in the proper position for coupling, the fifth wheel should:

be tilted down towards the rear of the tractor.
be level with the ground.
tilted up towards the rear of the tractor.
have its jaws closed around the shank of the kingpin.

8. The front trailer supports are up, and the trailer is resting on the tractor. Make sure:

the electrical and air connections are properly connected between the tractor and the trailer.
there is enough clearance between the top of the tractor tires and the nose of the trailer.
there is enough clearance between the rear of the tractor frame and the landing gear.
All of the above.

9. In combination vehicles with air brakes, the trailer air supply control:

is used to keep the trailer behind the tractor.
supplies air to the trailer air tanks.
is a coupling devices used to connect the service and emergency air-lines from the tractor to the trailer.
is used to control the tractor protection valve.

10. Which of the following is most likely to roll over?

The middle trailer of a triple
The front trailer of a double
The rear trailer of a double
The rear trailer of a triple

DC CDL COMBINATION PRACTICE TEST