CDL Double-Triple
Trailers Test

This is the Commercial Vehicle Driver's License Test covering Double and Triple Trailers. You will be presented with 40 questions and you must answer 34 questions correctly to pass. There is no time limit. You may not go back once you answer a question. Click the "Start Quiz" button below to begin. Good luck!

1 / 40

Why should you test the tractor protection valve?

to avoid loss of air from the trailer brakes

all answers listed

to avoid the emergency brakes kicking on due to loss of air

to avoid loss of air from the air hose

2 / 40

Select the true statement about double or triple trailers.

they present a rearward amplification hazard

they can roll over duee to abrupt steering movements

all answers listed

they can have a dangerous "crack the whip" effect

3 / 40

Select the action that is not recommended when driving on slipper roads:

none of the answers listed

use a speed retarder or engine brake

keep other drivers out of your side space

use a light pressure with the the brake and accelerator pedals

4 / 40

In what position should the shut off valves on a the rear of the front trailer be in on a set of double trailers?

in a halfway open position

in an open position

in a closed position

in a 1/3 way open position

5 / 40

Select the statement that is true in regards to what is required of a driver with a double or triple trailers:

drive with extra care in mountains and in bad weather

none of the answers listed

all of the answers listed

increase your following distance

6 / 40

Do converter dollies have spring brakes?

yes

some do

none of the answers listed

7 / 40

You should check your mirrors while making a lane change:

after you signal your intent to change lanes

all answers listed

right after you start the lane change

after you have completed the lane change

8 / 40

Which trailer should be the first one after the tractor?

the trailer that weighs the least

the trailer that is the shortest in length

the trailer that weighs the most

none of the answers listed

9 / 40

How do you check the air flow to the last trailer?

watch the brake lights as you step on the brake pedal

while on an level surface, test the emergency brake lines

pull the vehicle forward and then step on the brakes

listen for escaping air after opening the emergency shut off valve

10 / 40

You can be sure air is supplied to the second trailer by:

watch the air gauge for a drop of 30 psi

going to the rear of the second trailer and open the emergency line shut off

while driving at 10 mph apply the hand valve you should stop at the same in the same distance as a single trailer driving at 5 mph

you should get out and listen for air flowing through the lines

11 / 40

The best way to have control on curves is:

to decrease to your safe speed before entering the curve and then accelerate through it

to shift to a lower gear before entering the curve

keep pressure on the brake pedal through the turn

you do not need to do anything different

12 / 40

You don't want to use wheel chocks when hooking a combination to a second trailer with no spring brakes. What should you do?

use a portable generator to supply brake pressure

make sure the trailer will not roll away when coupling

none of the answers listed

supply air to the trailer air system via the tractor and then disconnect the emergency line

13 / 40

Your rig should be parked on__to uncouple double trailers.

level ground

grass

the company's lot

a downgrade

14 / 40

Select the true statement in regards to converter dollies:

they typically have small braking power because of their size

they typically require a hand converter

they typically have a lot of stopping power because of their size

they typically do not have spring brakes

15 / 40

You should keep a minimum of ____between another vehicle and the double trailer with 100 ft truck driving at 30 mph.

13 seconds

15 seconds

8 seconds

10 seconds

16 / 40

The trailer height is correct for connecting a converter dolly to a second trailer when:

the trailer will slightly rise when the converter dolly is backed under it

the top of the kingpin lines up with the locking jaws

the trailer will slightly lower when the converter dolly backed under it

the kingpin is resting behind the fifth wheel

17 / 40

What is most likely to occur when driving double and a set of trailer wheels goes into a skid?

the rig will continue straight ahead but will slide sideways

the tractor will continue moving in a straight line no matter how you turn the steering wheel

the trailer will jackknife

none of the answers listed

18 / 40

Remember to____when connecting the converter dolly to the rear trailer.

all answers listed

check the trailer height

lock the trailer brakes

ensure that the landing gear is slighty off of the ground

19 / 40

Select the true statement in regards to unhooking the pintle hook while the converter dolly is still under the trailer.

this is recommended because it keeps the trailer from tipping over

this is not recommended as it could could cause damage to the pintle hook

this is recommended as it is standard procedure

this is not recommended because it may result in injury

20 / 40

What is the best way to stop all skids?

accelerate and countersteer

restore traction back to the tires

quickly turn the steering wheel side to side

use controlled or stab braking

21 / 40

When driving with multiple trailers, which one should be right behind the tractor?

the trailer with the heaviest load

the trailer with the smallest road

the trailer longest in length

the trailers shortest in length

22 / 40

What is most likely to occur when driving a set of doubles and a set of trailer wheels goes into a skid?

nothing will occur

there will be a trailer jackknife

the rig will slide sideways but stay in a straight line

no matter how you turn the steering wheel, the rig will continue in a straight line

23 / 40

In what position should shut off valves on the rear of the last trailer be in on a set of double trailers?

in a closed position

in a closed position for the rear trailer and open position for the front trailers

in a open position for the rear trailer and a closed position for the front trailer

in a open position

24 / 40

What should you hear when you test the trailer brakes by opening the service air line at rear of trailer with the hand valve on?

none of the answers listed

you should hear air escape from the open valve

the emergency air line will release air

the service brakes will move to a fully applied position

25 / 40

How should the shut off valves at the rear of the trailer be when inspecting doubles?

closed at the rear of the last trailer and open at the rear of the front trailer

closed at the rear of the last trailer and front trailer

none of the answers listed

open at the rear of the last trailer and front trailer

26 / 40

In what position should the converter dolly air tank drain valve be in for double trailer combination?

in an open position

in a 1/3 open position

in a closed position

in a halfway closed position

27 / 40

How do you make sure the trailer height is correct before coupling?

visually check that the lead trailer is higher than the fifth wheel so that the trailer will lower when the dolly is pushed under it

visually check that they are level height wise

visually check that the rear trailer is lower than the fifth wheel so that the trailer raises slightly when the dolly is pushed under it

you do not need to do a visual check

28 / 40

Select the action that is not appropriate when driving on slippery roads:

use a light pressure on the brake and accelerator pedals

avoid having traffic in your side space

none of the answers listed

use a speed retarder or engine brake

29 / 40

What is the minimum amount of distance you should maintain when driving at 50 mph in ideal conditions with a 100 ft twin trailer combination?

8 seconds

11 seconds

6 seconds

13 seconds

30 / 40

Select the true statement about converter dollies:

because of their small size they have little braking power

all answers listed

they usually do not have spring brakes

they typically require a glad hand converter

31 / 40

The main reason you should pull the dolly out from under a trailer before disconnecting it from the trailer in front is:

to provide additional lateral stabilization to the front trailer

it is possible that the dolly tow bar could fly up making it difficult to re-couple

so the rear-trailer's air brake system will stay charged and keep the trailer wheels locked to prevent rolling

removing the dolly before uncoupling is not the correct procedure

32 / 40

Which trailer is most likely to tip over due to the crack the whip effect?

the heaviest trailer

the last trailer of a double

the last trailer of a triple

the first trailer of a triples

33 / 40

You should_____to uncouple the converter dolly.

disconnect the safey chains, lower the landing gear, and chock the wheels

lower the landing gear, disconnect the safety chain, and chock the wheels

chock the wheels, disconnect the safety chains, and then lower the landing gear

chock the wheels, lower the landing gear, and disconnect the safey chains

34 / 40

Where are shut off valves located on trailers that are doubles or triples?

on emergency air lines

on parking brake lines

on service air lines

on emergency and service air lines

35 / 40

What will probably happen if the converter dolly is still under the second trailer and the pintle hook is unhooked?

the engine brakes will unlock

the dolly tow bar could fly up

nothing will happen

the air lines will explode

36 / 40

How should you inspect a converter dolly?

as if it is cargo

as if it is an engine

as if it is an axle with a fifth wheel

as if it is a trailer

37 / 40

How do you hook a combination to a second trailer without spring brakes and without using wheel chocks?

make sure th trailer won't roll when coupling

go ahead and couple it

have the trailer electric cord to a generator so it can supply braking power

disconnect the air supply lines after supplying air to the trailer air system via the tractor

38 / 40

The pintle hook should be_____ and the converter dolly air tank drain valve is___when doing a walk around inspection of a triple or double trailer.

latched, open

free, open

latched, closed

free, closed

39 / 40

What position should the heaviest trailer be in when pulling 3 trailers?

in the front

in the middle

it makes no difference

in the back

40 / 40

Select the true statement about seeing ahead.

all answers listed

you should look up to 1/4 mile ahead when driving at highway speeds

good drivers will shift their attention from far and near and back and forth

many individuals do not look far enough ahead while driving

Your score is

The average score is 0%

4/5 - (2 votes)

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