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

the truck requires increased following distance compared to smaller vehicles

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

2 / 40

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

the fifth wheel may be misaligned

the dolly tow bar may fly up

the spring brakes may release

the kingpin may snap in half

3 / 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?

13 seconds

11 seconds

6 seconds

8 seconds

4 / 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 emergency air line will release air

the service brakes will move to a fully applied position

none of the answers listed

you should hear air escape from the open valve

5 / 40

Select the true statement in regards to empty trucks:

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

none of the answers listed

they require a shorter stopping distance than a fully loaded trailer

they may have poor traction due to bouncing and wheel lockup

6 / 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 an open position

in a halfway open position

in a closed position

in a 1/3 way open position

7 / 40

Select the true statement about double or triple trailers.

all answers listed

they can have a dangerous "crack the whip" effect

they can roll over duee to abrupt steering movements

they present a rearward amplification hazard

8 / 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

none of the answers listed

make sure the trailer will not roll away when coupling

use a portable generator to supply brake pressure

9 / 40

Select the true statement about converter dollies:

all answers listed

they typically require a glad hand converter

they usually do not have spring brakes

because of their small size they have little braking power

10 / 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?

11 / 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 trailer will jackknife

none of the answers listed

the rig will continue straight ahead but will slide sideways

12 / 40

Select the true statement about seeing ahead.

good drivers will shift their attention from far and near and back and forth

many individuals do not look far enough ahead while driving

all answers listed

you should look up to 1/4 mile ahead when driving at highway speeds

13 / 40

Remember to_____when steering to avoid a crash while driving doubles.

keep your foot off the brake while turning

be prepared to counter-steer

have both hands on the steering wheel

all answers listed

14 / 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 200 feet which is 2/3 of a football field

about 600 feet with is about two football field lengths

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

15 / 40

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

when the tractor brakes lock up

when the trailer pushes the towed vehicle sideways

when the tractor spins around

when the trailer slides to the right into the shoulder

16 / 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 do not have spring brakes

they typically have small braking power because of their size

17 / 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

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.

latched, open

latched, closed

free, closed

free, open

19 / 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

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

make sure th trailer won't roll when coupling

20 / 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

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

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

crank the engine brake

21 / 40

Select the true statement about empty trucks:

they have poor traction due to wheel lockup and bouncing

they have a smaller stopping distance than full trailers

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

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

22 / 40

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

it is easier to countersteer compared to other vehicles

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

there are no issues that occur from quick steering

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

23 / 40

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

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

to provide additional lateral stabilization to the front trailer

removing the dolly before uncoupling is not the correct procedure

24 / 40

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

in the back

in the front

it makes no difference

in the middle

25 / 40

You should_____to uncouple the converter dolly.

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

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

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

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

26 / 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

open the shut off valve at the back of both trailers

close the shut off valves at the back of each trailer

none of the answers listed

27 / 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

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

all answers listed

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

28 / 40

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

open and open

closed and open

open and latched

closed and latched

29 / 40

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

keep other drivers out of your side space

use a light pressure with the the brake and accelerator pedals

none of the answers listed

use a speed retarder or engine brake

30 / 40

You should check your mirrors while making a lane change:

right after you start the lane change

after you signal your intent to change lanes

after you have completed the lane change

all answers listed

31 / 40

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

on service air lines

on parking brake lines

on emergency and service air lines

on emergency air lines

32 / 40

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

listen for escaping air after opening the emergency shut off valve

while on an level surface, test the emergency brake lines

watch the brake lights as you step on the brake pedal

pull the vehicle forward and then step on the brakes

33 / 40

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

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

the kingpin is over the fifth wheel

all answers listed

the center of the kingpin is past the locking jaw

34 / 40

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

the last trailer of a double

the heaviest trailer

the first trailer of a triples

the last trailer of a triple

35 / 40

Why should you test the tractor protection valve?

to avoid loss of air from the air hose

to avoid loss of air from the trailer brakes

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

all answers listed

36 / 40

The best way to have control on curves is:

to shift to a lower gear before entering the curve

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

you do not need to do anything different

keep pressure on the brake pedal through the turn

37 / 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?

the service brakes more to a fully applied position

air leaving the open valve

the emergency line valve to release air

the engine brake to kick on

38 / 40

Start by___when coupling.

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

having the second trailer against the dock

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

in a open position

in a closed position

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

40 / 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

drive at a high speed

shift into a lower gear

increase engine rpm

Your score is

The average score is 83%

4/5 - (2 votes)

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