COMBINATION CDL TEST – 01

The combination CDL test will examine your knowledge of driving combinations, combination vehicle air brakes, antilock brake systems, coupling and uncoupling, and inspecting combinations. In order to receive your combination vehicle endorsement, it is required that you pass the state’s official CDL written Knowledge exam.

Combination Test 01

1 / 30

A rig with triple 27 foot trailers is how much more likely to roll in a crash than a five axle tractor semitrailer of 45 feet?

2.5 times

4.5 times

1.5 times

3.5 times

2 / 30

To regain control of a trailer which is jackknifing, you should...?

Increase foot brake pressure

Apply the handbrake

Accelerate

Release the foot brake

3 / 30

Before reversing a trailer, you should...?

Shout a warning

Rev your engine loudly

Walk all around the vehicle

Sound your horn several times

4 / 30

When pulling a trailer, you should aim to make your steering...?

Harsh and swift

Firm and slow

Smooth and swift

Gentle and smooth

5 / 30

The tractor protection valve will be activated if air pressure falls below...?

20 – 45 psi

30 – 55 psi

45 – 65 psi

15 – 30 psi

6 / 30

Jackknifing is more likely to happen when a trailer is...?

Fully loaded

Empty

Three quarters loaded

Half loaded

7 / 30

The service air line is controlled by...?

The foot brake only

The trailer air supply control

The trailer handbrake only

The foot brake or the trailer handbrake

8 / 30

You have to make a right turn that can only be completed by using another traffic lane. You should...?

Swing wide on exit

Swing wide at the beginning

Swing wide half way through

Any of these

9 / 30

In a vehicle with air brakes, the trailer hand valve should only be used for...?

Make emergency stops

Making slow speed stops

Testing the brakes

Making high-speed stops

10 / 30

The emergency air line is usually colored what?

Yellow

Red

Green

Blue

11 / 30

You should add at least an extra second to your following distance to other vehicles if you are traveling in excess of...?

60 mph

40 mph

50 mph

30 mph

12 / 30

The most frequent cause of rollover is...?

Turning too fast

Turning at too shallow an angle

Turning at too sharp an angle

Turning too slowly

13 / 30

Your following distance to other vehicles when driving with a trailer should be at least one second for every...?

7.5 feet of vehicle length

15 feet of vehicle length

5 feet of vehicle length

10 feet of vehicle length

14 / 30

When air is let out of the trailer emergency line, what happens?

The truck emergency brakes apply

The truck loses all braking power

The trailer emergency brakes apply

The trailer loses all braking power

15 / 30

Which of these will help to prevent rollover?

Keeping the cargo as far to the back as possible

Keeping the cargo as low as possible

Keeping the cargo as far to the front as possible

Keeping the cargo as high as possible

16 / 30

Truck rollovers are responsible for what percentage of driver deaths in truck crashes?

20% plus

50% plus

40% plus

30% plus

17 / 30

If you are using a trailer which does not have spring brakes, you should...?

Wedge the foot brake down when parked

Always park facing uphill

Always park facing a wall or other solid object

Always use chocks under the wheels when parked

18 / 30

Large combination vehicles take longer to stop when...?

They are fully loaded

They are 75% loaded

They are empty

They are 50% loaded

19 / 30

Which of these vehicles is most likely to get stuck on a railroad crossing?

A single tractor and trailer

A car mover

A tractor and double trailer

A tractor and triple trailer

20 / 30

If your vehicle gets stuck on a railroad crossing, what should you do?

Stay by the vehicle

Ask others to tow your vehicle

Evacuate the vehicle

Stay in the vehicle

21 / 30

You should check in your mirrors to see if your trailer is in the correct position every time you...?

Brake hard

Leave the highway

Accelerate

Pull into a parking lot

22 / 30

How much more likely is a truck to roll over if it is fully loaded, compared to an empty rig?

10 times

2 times

5 times

15 times

23 / 30

When backing up with a trailer, you should start the maneuver by turning the steering wheel...?

In the direction you want to go

Any of these depending on length of trailer

So it is set straight ahead

Opposite the direction you want to go

24 / 30

The longer your trailer is, the more the path of your rear wheels will...?

Do any of these depending on road conditions

Follow a wider line than your tractor

Follow the same line as your tractor

Follow a tighter line than your tractor

25 / 30

The tractor protection valve keeps air in the tractor or truck brake system if...?

The tractor/trailer air hose is severed

The air system develops a bad leak

The tractor breaks away from the trailer

Any of these things happen

26 / 30

Ideally, when you have to back up a trailer, you should position your vehicle so you come back...?

Curving to the right

In a straight line

Curving to the left

It makes no difference

27 / 30

The earliest and best way to learn that your trailer has started to skid is...?

Seeing it in your mirrors

Hearing the tires squeal

Feeling it through the steering wheel

Being warned by other road users

28 / 30

Which of these is one of the first things you should do if your vehicle becomes stuck on a railroad crossing?

Call your employer

Call 911

Call a tow truck

Call the railroad company

29 / 30

On newer vehicles, the trailer air supply control will be a knob of which color?

Yellow

Green

Blue

Red

30 / 30

When making a right-hand turn, you should aim to stop other drivers...?

Passing you on the right

Having to stop for you

Getting too close to your rear bumper

Passing you on the left

Your score is

Studying and applying oneself is the only way to successfully learn the information you need to know to pass all testing required to obtain your CDLs. We are here to help.

Don’t hesitate to take advantage of our practice tests in each category specific to your needs. We wish you the best of luck in your endeavors and are pleased to be of assistance.