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

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

shift into a lower gear

drive at a high speed

quickly turn the steering wheel side to side

increase engine rpm

2 / 40

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

use the trailer brakes only

slam down the brake pedal and keep pressure on it

none of the answers listed

do stab or controlled braking

3 / 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

4 / 40

Select the true statement about convex ("spot") mirrors.

you do not need to look at them as often as flat mirrors

they are against the law in the majority of states

they make things closer and larger than they really are

they make things look farther away and smaller than they actually are

5 / 40

Your rig should be parked on__to uncouple double trailers.

a downgrade

grass

level ground

the company's lot

6 / 40

You should check your mirrors while making a lane change:

right after you start the lane change

all answers listed

after you signal your intent to change lanes

after you have completed the lane change

7 / 40

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

true

only on downgrades

only in ideal conditions

false

8 / 40

What is the best way to stop all skids?

quickly turn the steering wheel side to side

use controlled or stab braking

restore traction back to the tires

accelerate and countersteer

9 / 40

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

make things look farther away and smaller than they actually are

are illegal in most states

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

10 / 40

The best way to have control on curves is:

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

to shift to a lower gear before entering the curve

11 / 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 dolly tow bar could fly up

the engine brakes will unlock

the air lines will explode

12 / 40

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

none of the answers listed

use a light pressure with the the brake and accelerator pedals

keep other drivers out of your side space

use a speed retarder or engine brake

13 / 40

Select the true statement in regards to converter dollies:

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

they typically do not have spring brakes

they typically require a hand converter

they typically have small braking power because of their size

14 / 40

Select the true statement about converter dollies:

they usually do not have spring brakes

all answers listed

because of their small size they have little braking power

they typically require a glad hand converter

15 / 40

Select the true statement in regards to a converter dolly:

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

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 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

16 / 40

What should you hear when you have the hand valve on and are testing the trailer brakes by opening the service air line at the back of the trailer?

air leaving the open valve

the service brakes more to a fully applied position

the emergency line valve to release air

the engine brake to kick on

17 / 40

Select the true statement about handling triples and doubles:

triples and doubles handle the same as singles

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

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

18 / 40

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

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

the rig will slide sideways but stay in a straight line

there will be a trailer jackknife

nothing will occur

19 / 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?

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

use a portable generator to supply brake pressure

none of the answers listed

make sure the trailer will not roll away when coupling

20 / 40

The correct trailer height when coupling the rear trailer is:

the kingpin is touching the fifth wheel

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

when the locking jaws are open around the kingpin

slightly lower than the center of the fifth wheel

21 / 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

all answers listed

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

22 / 40

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

by opening the air tank petcock

by charging the air line

by flushing the brake line

by opening the shut off valve

23 / 40

Do converter dollies have spring brakes?

yes

none of the answers listed

some do

24 / 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

25 / 40

Select the statement that is true in regards to managing space to the sides.

all answers listed

high gust winds do not cause any issues for triples and doubles

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

you should try to avoid driving next to others when possible

26 / 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

27 / 40

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

use a speed retarder or engine brake

use a light pressure on the brake and accelerator pedals

none of the answers listed

avoid having traffic in your side space

28 / 40

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

in the back

it makes no difference

in the front

in the middle

29 / 40

Select the true statement in regards to driving a truck with triple or double trailers:

all answers listed

the truck requires increased following distance compared to smaller vehicles

extra care should be taken when driving in bad weather and in the mountains

the risk of trailer jackknifes and tipping is increased compared to shorter trucks

30 / 40

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

only in a level loading dock

false

true

only at the end of a shift

31 / 40

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

the last trailer of a double

a fully loaded trailer behind the tractor

any trailer

the last trailer of a triple

32 / 40

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

on emergency air lines

on service air lines

on emergency and service air lines

on parking brake lines

33 / 40

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

use the trailer brakes only

use the stab braking method

drive at a speed of 5 mph below your safe speed

use countersteering practices

34 / 40

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

the center of the kingpin is past the locking jaw

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

all answers listed

the kingpin is over the fifth wheel

35 / 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

crank the engine brake

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

36 / 40

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

open and open

closed and latched

closed and open

open and latched

37 / 40

Select the true statement in regards to handing triples and doubles

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

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

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

38 / 40

What is the stopping distance for a tractor trailer that is traveling at 55 mph on dry pavement?

about 300 feet which is about a football field length

about 600 feet with is about two football field lengths

about 200 feet which is 2/3 of a football field

about 150 feet which is 1/2 of a football field

39 / 40

How should you inspect a converter dolly?

as if it is an axle with a fifth wheel

as if it is cargo

as if it is a trailer

as if it is an engine

40 / 40

Which trailer should be the first one after the tractor?

the trailer that weighs the most

none of the answers listed

the trailer that weighs the least

the trailer that is the shortest in length

Your score is

The average score is 83%

4/5 - (2 votes)

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