CLP - Commercial Learner's Permit Combination Vehicle Operations Questions and Answers

Question 1

When driving a combination vehicle, the 'crack-the-whip' effect is a significant danger. Which of the following is most likely to cause the rear trailer to roll over?

Accepted Answer

Making a sudden or quick lane change.

Answer

Driving slowly around a wide, sweeping curve.

Answer

Applying the trailer hand brake firmly while turning.

Answer

Accelerating smoothly on a straight highway.

Question 2

You are coupling a tractor to a semitrailer. Before you back under the trailer, the trailer is at the correct height when:

Accepted Answer

The trailer will be raised slightly when the tractor backs under it.

Answer

The landing gear is fully retracted and off the ground.

Answer

The kingpin is about two inches lower than the fifth wheel.

Answer

The fifth wheel makes firm contact with the trailer apron without lifting it.

Question 3

A driver is operating a tractor without a trailer attached, a practice known as 'bobtailing'. Compared to a fully loaded tractor-trailer, how does a bobtail tractor's stopping distance change?

Accepted Answer

It can be longer because there is less weight on the drive axles for traction.

Answer

It is significantly shorter due to the reduced weight.

Answer

It is about the same, as the brakes are designed for the tractor.

Answer

It depends entirely on the road surface condition.

Question 4

What is the primary, approved use of the trailer hand valve (also known as the trolley valve or Johnson bar)?

Accepted Answer

To test the trailer service brakes.

Answer

To prevent the vehicle from rolling back on a hill.

Answer

To assist with making tight turns.

Answer

For regular parking instead of the spring brakes.

Question 5

When a combination vehicle turns a corner, the rear wheels of the last trailer follow a different path than the front wheels of the tractor. This is called:

Accepted Answer

Off-tracking

Answer

Rearward amplification

Answer

Axle drift

Answer

Yaw instability

Question 6

Which of the following statements about inspecting a combination vehicle is TRUE?

Accepted Answer

A lack of grease on the fifth wheel plate can cause steering problems.

Answer

There should be a noticeable gap between the upper and lower fifth wheel after coupling.

Answer

The landing gear should be raised only until it just lifts off the pavement before driving.

Answer

The safety latch for the fifth wheel jaw should be in the open position for driving.