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

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 for the rear trailer and open position for the front trailers

in a open position

in a closed position

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

2 / 40

Mirrors with a convex surface or "spot" mirrors _____.

make things look closer and larger than they actually are

they show a larger area than flat mirrors so do not need to be checked as often

are illegal in most states

make things look farther away and smaller than they actually are

3 / 40

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

on parking brake lines

on emergency and service air lines

on emergency air lines

on service air lines

4 / 40

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

you do not need to do a visual check

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

visually check that they are level height wise

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

5 / 40

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

removing the dolly before uncoupling is not the correct procedure

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

6 / 40

What do you need to do to supply air to the air tranks of the second trailer?

open up the shutt off valves on the rear of the first trailer and close the shut off valve at the back of the second trailer

none of the answers listed

open the shut off valve at the back of both trailers

close the shut off valves at the back of each trailer

7 / 40

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

it makes no difference

in the middle

in the front

in the back

8 / 40

Select the true statement about empty trucks:

empty trucks stop in the same distance as a fully loaded truck

empty trailers are easier to stop because there is not cargo shifting

they have a smaller stopping distance than full trailers

they have poor traction due to wheel lockup and bouncing

9 / 40

What are the 3 methods for securing a second trailer before coupling?

all answers listed

chocking the tires, parking on level ground, and charging the air tank

parking against another trailer, locking the trailer door, and chocking the tires

parking on level ground, chocking the tires, and charging the trailer air tank if it doesn't have spring brakes

10 / 40

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

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

watch the air gauge for a drop of 30 psi

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

11 / 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 1/3 way open position

in a closed position

12 / 40

What should you check for when inspecting a converter dolly?

all answers listed

that the spare tire is secured if there is one

that the converter dolly air tank drain valve is in the closed position

that the safety chains are secured to the trailer

13 / 40

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

the heaviest trailer

the first trailer of a triples

the last trailer of a triple

the last trailer of a double

14 / 40

Select the true statement about converter dollies:

because of their small size they have little braking power

they usually do not have spring brakes

all answers listed

they typically require a glad hand converter

15 / 40

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

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

the rig will continue straight ahead but will slide sideways

the trailer will jackknife

none of the answers listed

16 / 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

17 / 40

Remember to____when connecting the converter dolly to the rear trailer.

check the trailer height

lock the trailer brakes

ensure that the landing gear is slighty off of the ground

all answers listed

18 / 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.

free, closed

latched, open

free, open

latched, closed

19 / 40

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

the trailers shortest in length

the trailer with the smallest road

the trailer with the heaviest load

the trailer longest in length

20 / 40

Which trailer should be the first one after the tractor?

the trailer that weighs the most

the trailer that weighs the least

none of the answers listed

the trailer that is the shortest in length

21 / 40

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

nothing will happen

the engine brakes will unlock

the dolly tow bar could fly up

the air lines will explode

22 / 40

Select the true statement in regards to quick steering movements and double trailers:

nothing will occur

you should apply a firm pressure to the brake pedal at the same moment you do quick steering movements

it is easier to tip doubles and triples from quick steering movements than other vehicles

it is easier to countersteer doubles/triples than other vehicles

23 / 40

Select the true statement about handling triples and doubles:

a tip over of the rear trailer can occur due to sudden movements of the steering wheel

triples and doubles handle the same as singles

because of the crack the whip effect, the rear trailer of a 100-foot triple is less likely to tip over

due to off-tracking, a triple bottom rig can come to a stop faster than a 5-axle tractor

24 / 40

Start by___when coupling.

having the second trailer against the dock

coupling the tractor to the second trailer

backing the converter dolly under the second trailer

coupling the converter hook to the pintle tongue of the first trailer

25 / 40

You should_____to uncouple the converter dolly.

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

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

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

26 / 40

Select the true statement in regards to converter dollies:

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

they typically require a hand converter

they typically have small braking power because of their size

they typically do not have spring brakes

27 / 40

Why should you test the tractor protection valve?

to avoid loss of air from the trailer brakes

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

to avoid loss of air from the air hose

all answers listed

28 / 40

You should look into the back of the fifth wheel on a dolly to see if it is locked onto the kingpin.

false

only at the end of a shift

only in a level loading dock

true

29 / 40

The crack-the-whip effect is more likely to cause the front trailer to tip over.

false

trailers never tip

there is an equal chance for trailers to tip

true

30 / 40

What is the best way to prevent brakes form overheating while drive down a steep grade?

use countersteering practices

use the trailer brakes only

drive at a speed of 5 mph below your safe speed

use the stab braking method

31 / 40

How much space should you see between the lower and upper fifth wheel when checking the coupling of a converter dolly?

1 to 1 1/2 inches

1/2 to 1 inch

it depends on how heavy the load is

none

32 / 40

In what position should the converter dolly air tank drain valves and pintle hook be in?

open and latched

closed and latched

open and open

closed and open

33 / 40

The driver's manual advises you to disconnect the steering axle brake to keep the rig straight:

never

in ideal conditions

whever you feel like it

when it is raining

34 / 40

How much space should there be between the lower and upper fifth wheel?

zero

1/4 to 1/2 of an inch

1 to 2 inches

it is dependent on the load you are carrying

35 / 40

Select the statement of what you should not do if you are required to drive through flowing water or deep puddles.

increase engine rpm

shift into a lower gear

drive at a high speed

quickly turn the steering wheel side to side

36 / 40

Select the true statement in regards to a converter dolly:

it is a coupling device with only two axles and a sixth wheel to which a semitrailer can be coupled to the rear of a tractor-trailer combination forming a double bottom rig

it is a coupling device with one or two axles and a fifth wheel with which a semitrailer can be coupled to the rear of a tractor-trailer combination forming a double bottom rig

it is a connecting device consisting of one axle which disconnects a semitrailer combination vehicle converting it into two separate trailers

none of the answers listed

37 / 40

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

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

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

make sure th trailer won't roll when coupling

go ahead and couple it

38 / 40

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

use a light pressure on the brake and accelerator pedals

use a speed retarder or engine brake

avoid having traffic in your side space

none of the answers listed

39 / 40

What method should be used to test that the air is flowing to all the trailers?

listen for air flow after opening the shutoff valves at the rear of the last trailer

pump the brakes with the windows down

check the pressure indicator dial on the final trailer

only a certified mechanic can check for this

40 / 40

Select the true statement about double or triple trailers.

they can roll over duee to abrupt steering movements

they can have a dangerous "crack the whip" effect

they present a rearward amplification hazard

all answers listed

Your score is

The average score is 82%

4/5 - (2 votes)

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