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

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?

the service brakes will move to a fully applied position

the emergency air line will release air

none of the answers listed

you should hear air escape from the open valve

2 / 40

Select the true statement in regards to managing the space to the sides:

you should try to avoid driving next to others when possible

you should always keep your vehicle to the right side of the lane

you should drive down the center of both lanes over the pavement markings

high wind gusts will not cause any issues for doubles or triples

3 / 40

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

in the front

it makes no difference

in the back

in the middle

4 / 40

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

watch the brake lights as you step on the brake pedal

pull the vehicle forward and then step on the brakes

while on an level surface, test the emergency brake lines

listen for escaping air after opening the emergency shut off valve

5 / 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

it depends on how heavy the load is

none

1/2 to 1 inch

6 / 40

For emergency braking when driving a double trailer and having to use your brakes to avoid a collision is to:

use stab or controlled braking

use just the trailer brakes

use the engine brake

apply a firm pressure to the brake pedal and don’t let off

7 / 40

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

none of the answers listed

the rig will continue straight ahead but will slide sideways

the trailer will jackknife

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

8 / 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

increase your following distance

all of the answers listed

9 / 40

Select the true statement about seeing ahead.

many individuals do not look far enough ahead while driving

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

all answers listed

10 / 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?

11 seconds

6 seconds

13 seconds

8 seconds

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 closed position

in a 1/3 way open position

12 / 40

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

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

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

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

all answers listed

13 / 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

14 / 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

15 / 40

How do you release the dolly brakes when coupling twin trailers?

by flushing the brake line

by opening the shut off valve

by charging the air line

by opening the air tank petcock

16 / 40

Select the true statement about converter dollies:

they usually do not have spring brakes

they typically require a glad hand converter

because of their small size they have little braking power

all answers listed

17 / 40

Remember to____when connecting the converter dolly to the rear trailer.

ensure that the landing gear is slighty off of the ground

check the trailer height

all answers listed

lock the trailer brakes

18 / 40

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

drive at a high speed

increase engine rpm

quickly turn the steering wheel side to side

shift into a lower gear

19 / 40

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

open and open

open and latched

closed and open

closed and latched

20 / 40

Why is it dangerous to unlock the pintle hook with the dolly still under the rear trailer?

the kingpin may snap in half

the dolly tow bar may fly up

the fifth wheel may be misaligned

the spring brakes may release

21 / 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

22 / 40

To be sure that air is supplied to the second trailer:

keep an eye of the air gauge for a drop of 30 psi

open the emergency line shut off at the back of the second trailer

while driving at 10 mph, use the hand valve. The vehicle should stop in the same distance of a single trailer moving at 5 mph

crank the engine brake

23 / 40

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

close the shut off valves at the back of each trailer

open the shut off valve at the back of both trailers

none of the answers listed

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

24 / 40

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

the last trailer of a double

the first trailer of a triples

the last trailer of a triple

the heaviest trailer

25 / 40

Start by___when coupling.

having the second trailer against the dock

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

coupling the tractor to the second trailer

backing the converter dolly under the second trailer

26 / 40

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

use the trailer brakes only

use countersteering practices

use the stab braking method

drive at a speed of 5 mph below your safe speed

27 / 40

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

go ahead and couple it

make sure th trailer won't roll when coupling

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

28 / 40

How should you inspect a converter dolly?

as if it is cargo

as if it is a trailer

as if it is an axle with a fifth wheel

as if it is an engine

29 / 40

Which trailer should be the first one after the tractor?

the trailer that weighs the least

the trailer that weighs the most

the trailer that is the shortest in length

none of the answers listed

30 / 40

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

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

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

31 / 40

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

8 seconds

15 seconds

13 seconds

10 seconds

32 / 40

Do converter dollies have spring brakes?

yes

some do

none of the answers listed

33 / 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

34 / 40

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

trailers never tip

there is an equal chance for trailers to tip

true

false

35 / 40

Select the true statement in regards to handing triples and doubles

due to off tracking, a triple bottom rig can come to a stop quicker than a 5 axle semi trailer

none of the answers listed

due to the crack the whip effect, the rear trailer of a 100 foot triple is less likely to tip than a single trailer

a sudden movement of the steering wheel may result in the rear trailer tipping over

36 / 40

Select the true statement about handling triples and doubles:

triples and doubles handle the same as singles

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

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

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

37 / 40

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

the dolly tow bar could fly up

the engine brakes will unlock

nothing will happen

the air lines will explode

38 / 40

Select the statement that is true in regards to quick steering movements and triple/double trailers:

there are no issues that occur from quick steering

it is easier to countersteer compared to other vehicles

they flip over due to quick steering movements a lot easier than other vehicles

as you perform quick steering movements you should apply pressure to the brake pedal

39 / 40

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

the trailer with the heaviest load

the trailers shortest in length

the trailer longest in length

the trailer with the smallest road

40 / 40

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

in a 1/3 open position

in a halfway closed position

in a closed position

in an open position

Your score is

The average score is 0%

4/5 - (2 votes)

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