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

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 trailers shortest in length

the trailer longest in length

2 / 40

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

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

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

crank the engine brake

3 / 40

The correct trailer height when coupling the rear trailer is:

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

when the locking jaws are open around the kingpin

the kingpin is touching the fifth wheel

slightly lower than the center of the fifth wheel

4 / 40

What should you check for when inspecting a converter dolly?

that the safety chains are secured to the trailer

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

all answers listed

that the spare tire is secured if there is one

5 / 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

6 / 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

increase your following distance

none of the answers listed

all of the answers listed

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

How do you secure a second trailer to your combination vehicle?

use the emergency air brakes or the trailer's spring brakes only

use emergency air brakes, spring brakes, and wheel chocks together

none of the answers listed

use wheel chocks only

9 / 40

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

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

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

10 / 40

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

never

whever you feel like it

in ideal conditions

when it is raining

11 / 40

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

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

you should try to avoid driving next to others when possible

all answers listed

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

12 / 40

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

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

they are against the law in the majority of states

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

they make things closer and larger than they really are

13 / 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

14 / 40

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

on service air lines

on emergency air lines

on emergency and service air lines

on parking brake lines

15 / 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

16 / 40

Select the true statement in regards to a converter dolly:

none of the answers listed

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

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

17 / 40

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

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

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

watch the air gauge for a drop of 30 psi

18 / 40

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

while on an level surface, test the emergency brake lines

listen for escaping air after opening the emergency shut off valve

watch the brake lights as you step on the brake pedal

pull the vehicle forward and then step on the brakes

19 / 40

Select the true statement about empty trucks:

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

they have a smaller stopping distance than full trailers

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

they have poor traction due to wheel lockup and bouncing

20 / 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

21 / 40

You should check your mirrors while making a lane change:

after you signal your intent to change lanes

after you have completed the lane change

all answers listed

right after you start the lane change

22 / 40

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

the last trailer of a triple

the last trailer of a double

the first trailer of a triples

the heaviest trailer

23 / 40

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

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

all answers listed

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

the truck requires increased following distance compared to smaller vehicles

24 / 40

Start by___when coupling.

backing the converter dolly under the second trailer

coupling the tractor to the second trailer

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

having the second trailer against the dock

25 / 40

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

none of the answers listed

slam down the brake pedal and keep pressure on it

use the trailer brakes only

do stab or controlled braking

26 / 40

When would a drive-wheel skid result in a jackknife when pulling doubles?

when the tractor spins around

when the tractor brakes lock up

when the trailer pushes the towed vehicle sideways

when the trailer slides to the right into the shoulder

27 / 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

28 / 40

Select the true statement about double or triple trailers.

they can have a dangerous "crack the whip" effect

they present a rearward amplification hazard

they can roll over duee to abrupt steering movements

all answers listed

29 / 40

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

true

false

only on downgrades

only in ideal conditions

30 / 40

What do yo uneed to do before supplying air to the air tanks of the second 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 second trailer and open the shut off valves at the back of the first 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 first and second trailer

31 / 40

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

none

1 to 1 1/2 inches

1/2 to 1 inch

it depends on how heavy the load is

32 / 40

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

it makes no difference

in the back

in the front

in the middle

33 / 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 1/3 way open position

in a halfway open position

in a closed position

in an open position

34 / 40

What is the best way to stop all skids?

accelerate and countersteer

use controlled or stab braking

quickly turn the steering wheel side to side

restore traction back to the tires

35 / 40

Remember to_____when steering to avoid a crash while driving doubles.

be prepared to counter-steer

have both hands on the steering wheel

all answers listed

keep your foot off the brake while turning

36 / 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?

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

use a portable generator to supply brake pressure

37 / 40

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

removed from the dolly

in the unlatched position

in the latched position

in a halfway open position

38 / 40

You should_____to uncouple the converter dolly.

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

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

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

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

39 / 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

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

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

40 / 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, closed

free, open

latched, closed

Your score is

The average score is 83%

4/5 - (2 votes)

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