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

drive at a speed of 5 mph below your safe speed

use the stab braking method

use the trailer brakes only

use countersteering practices

2 / 40

Select the true statement about handling triples and doubles:

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

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

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

3 / 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, closed

free, closed

latched, open

free, open

4 / 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

5 / 40

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

the trailer with the smallest road

the trailer longest in length

the trailer with the heaviest load

the trailers shortest in length

6 / 40

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

any trailer

a fully loaded trailer behind the tractor

the last trailer of a triple

the last trailer of a double

7 / 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

13 seconds

6 seconds

11 seconds

8 / 40

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

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

nothing will occur

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

9 / 40

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

1 to 2 inches

it is dependent on the load you are carrying

1/4 to 1/2 of an inch

zero

10 / 40

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

go ahead and couple it

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

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

11 / 40

The best way to have control on curves is:

to shift to a lower gear before entering the curve

you do not need to do anything different

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

keep pressure on the brake pedal through the turn

12 / 40

How should the pintle hook be when backing a dolly under the second trailer?

removed from the dolly

in a halfway open position

in the latched position

in the unlatched position

13 / 40

What do you check when doing a visual inspection of the coupling?

the locking jaw is closed around the kingpin and there is no space beween the lower and upper fifth wheel

none of the answers listed

that the locking jaw is open around the kingpin and that there is some space between the lower and upper fifth wheel

that the locking jaw is closed around the kingpin and that there is no space between the upper and lower fifth wheel

14 / 40

What is the best way to stop all skids?

quickly turn the steering wheel side to side

restore traction back to the tires

accelerate and countersteer

use controlled or stab braking

15 / 40

Start by___when coupling.

coupling the tractor to the second trailer

having the second trailer against the dock

backing the converter dolly under the second trailer

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

16 / 40

Double and triple trailers should be driven with care to avoid a rollover or jacknife.

only in ideal conditions

only on downgrades

true

false

17 / 40

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

all answers listed

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

the center of the kingpin is past the locking jaw

the kingpin is over the fifth wheel

18 / 40

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

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

use stab or controlled braking

use the engine brake

use just the trailer brakes

19 / 40

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

closed and open

open and latched

open and open

closed and latched

20 / 40

Do converter dollies have spring brakes?

none of the answers listed

some do

yes

21 / 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

use a speed retarder or engine brake

none of the answers listed

22 / 40

What should you check for when inspecting a converter dolly?

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

all answers listed

that the safety chains are secured to the trailer

that the spare tire is secured if there is one

23 / 40

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

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

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

24 / 40

For emergency braking to avoid a crash when driving a double trailer you should:

slam down the brake pedal and keep pressure on it

do stab or controlled braking

none of the answers listed

use the trailer brakes only

25 / 40

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

quickly turn the steering wheel side to side

increase engine rpm

shift into a lower gear

drive at a high speed

26 / 40

Select the true statement about converter dollies:

all answers listed

they usually do not have spring brakes

they typically require a glad hand converter

because of their small size they have little braking power

27 / 40

The correct trailer height when coupling the rear trailer is:

slightly lower than the center of the fifth wheel

when the locking jaws are open around the kingpin

there is 5 inches of space between the lower and upper fifth wheel

the kingpin is touching the fifth wheel

28 / 40

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

in the back

in the middle

in the front

it makes no difference

29 / 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 air lines will explode

the dolly tow bar could fly up

30 / 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

none of the answers listed

the emergency air line will release air

you should hear air escape from the open valve

31 / 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

none of the answers listed

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

32 / 40

What do yo uneed to do before supplying air to the air tanks of the second trailer?

open the shut off vavles at the back of the second trailer and close the shut off valves at the back of the first trailer

close the shut off valves at the back of the second trailer and open the shut off valves at the back of the first trailer

open the shut off valves at the back of the first and second trailer

close the shut off valves at the back of the first and second trailer

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

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

in a open position

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

35 / 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

36 / 40

If you are driving a 100-foot truck with double trailers at 30 mph in dry conditions, how many seconds of space should there be between your truck and other vehicles?

37 / 40

Select the true statement in regards to empty trucks:

they may have poor traction due to bouncing and wheel lockup

none of the answers listed

they are easier to stop because there isn't cargo shifting in the trailer

they require a shorter stopping distance than a fully loaded trailer

38 / 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 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

you do not need to do a visual check

39 / 40

Select the true statement in regards to converter dollies:

they typically do not have spring brakes

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

they typically have small braking power because of their size

they typically require a hand converter

40 / 40

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

15 seconds

13 seconds

8 seconds

10 seconds

Your score is

The average score is 82%

4/5 - (2 votes)

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