CDL Practice Test

This is an independent CDL knowledge practice test. It is not a state licensing examination or required ELDT training. A score or downloadable practice certificate does not award a CLP or CDL.

How to use the result

Read the relevant sections of your current state CDL manual before answering. Afterward, review each missed question, locate the supporting rule and explain why the other answers do not fit. Recheck uncertain answers against the official manual and your instructor. Do not treat a repeated high score as proof that you can safely inspect or operate a vehicle.

Choose supplemental topics for the class and endorsements you need. General workplace and lifestyle quizzes are optional and do not replace CDL subjects. Browse practice topics · Check the official CDL process.

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CDL Knowledge Practice Test

This independent practice quiz helps you identify CDL knowledge topics to study. It is not an official state exam, does not issue a license, and does not establish that you can safely operate a vehicle.

Review missed answers with your current state CDL manual and a qualified instructor. Use the result to choose your next study topic. A practice certificate records activity on this website; it is not proof of ELDT completion.

Enter your name and email to receive your practice test certificate.

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1 / 32

1. What is a common cause of tire fires?

Overinflated tires

Cold tires

Underinflated tires

All of the above

2 / 32

2. What is the best way to figure out how many seconds of following distance you have?

Get 1/4 closer to the car in front of you, then back off again. Multiply how long this took you by four to give the following distance.

Send a text message to a friend to text you back in ten seconds. See how far you have traveled in that time.

Wait until the vehicle ahead of you passes a shadow or landmark. Then count the seconds until you reach it.

Use the stopwatch on your cell phone to determine how long it takes you to reach a mile marker after the vehicle in front of you has passed it.

3 / 32

3. An anti-lock braking system (ABS) will

keep your wheels from locking when you brake hard.

increase your stopping distance.

let you drive faster.

increase your vehicle's stopping power.

4 / 32

4. The minimum tread depth for tires other than the front tires is

4/32 inch.

2/32 inch.

8/32 inch.

1 inch.

5 / 32

5. What is the main reason to perform a vehicle inspection?

Safety

To check the cleanliness of your vehicle

To make sure your paint is not chipped

Employer liability

6 / 32

6. Which of these is NOT part of the basic method for shifting up?

Releasing the clutch and pressing the accelerator at the same time

Releasing the clutch

Pushing in the clutch and shifting into a higher gear at the same time

Accelerating while pressing the clutch and turning toward the driver's side

7 / 32

What will help a drunk sober up?

Time

Fresh air

A glass of water

Coffee

8 / 32

8. How many reflective warning triangles must you carry with you for emergencies?

9 / 32

9. Which of the following are parts of the suspension system?

Bearing plate

All of the above

Pitman arm

Lock ring

10 / 32

10. In which of the following two situations should you downshift?

Starting down a hill and entering a curve

Starting up a hill and finishing a curve

Starting down a hill and finishing a curve

Starting up a hill and entering a curve

11 / 32

11. If you are confronted by an aggressive driver, you should

call the police from your cell phone if you can do it safely.

ignore rude gestures and refuse to react negatively.

avoid eye contact.

do all of the above.

12 / 32

12. If you're driving a vehicle with an automatic transmission, when should you downshift?

If you're going down a steep downgrade

When your engine speed increases

If you start to get drowsy

If you feel you're driving too fast

13 / 32

13. What are the main differences between aggressive driving and road rage?

Whether it's intentional

All of the above

The outcome of the situation

The level of anger

14 / 32

14. To maintain alertness during your trip, you should

schedule your trip for the daytime hours.

get 8–9 hours of sleep beforehand.

avoid medications that cause drowsiness.

do all of the above.

15 / 32

15. You should put the starter switch key into your pocket while you perform the pre-trip inspection because

it could damage the starting mechanism.

any of the above could occur.

someone could steal the truck.

someone could start and move the truck.

16 / 32

16. For how long will you lose your CDL privileges if you are convicted of a second DUI offense?

Three years minimum

Ten years minimum

Life

Five years minimum

17 / 32

17. Which of the following are serious traffic violations that may cause you to lose your CDL privileges?

All of the above

Traveling at 15 mph or more above the posted speed limit

Talking on a cell phone

Playing music too loudly

18 / 32

18. If the engine is not overheated, is it completely safe to remove the radiator cap?

Yes, as long as the radiator isn't damaged.

Yes.

Yes, as long as there is no overflow.

19 / 32

19. What is the best way to check what is happening behind and to the sides of your vehicle?

Adjust your mirrors before you start your trip and check them regularly.

Just turn your head and look at your blind spots.

Stop every 50 miles and look around.

Check your reflection in other vehicles.

20 / 32

20. You don't want to be a distracted driver, so you

read maps or use your phone only when there are no other vehicles around you.

smoke, eat, and drink only on straight portions of the road.

have all your emotionally difficult conversations in the first hour of driving.

avoid using your cell phone until you reach your destination.

21 / 32

21. On which of the following types of fires should you NOT use a B:C fire extinguisher?

Gasoline

Electrical

Grease

Wood

22 / 32

22. How long does it take a typical tractor-trailer to clear a double railroad track?

14 seconds

More than 15 seconds

10 seconds

More than 30 seconds

23 / 32

23.

Letting the air out of hot tires

will have no effect at all.

is a bad idea because when the tires cool off, the pressure will be too low.

is a good idea because the extra pressure will be relieved.

will cool them down. You will be able to continue your trip sooner.

24 / 32

24. Total stopping distance equals

Perception distance + reaction distance.

Perception distance + reaction distance + braking distance.

Reaction distance + braking distance + signal distance.

Reaction distance + braking distance.

25 / 32

25. How can you determine if your vehicle is equipped with an anti-lock braking system (ABS)?

Check for a yellow ABS malfunction lamp on the instrument panel.

Check if your vehicle was manufactured after March 1, 1998. (Such vehicles are required to have the panel light.)

Look for wheel speed sensor wires that are coming from the rear of your brakes.

All of the above can work.

26 / 32

26. It has just reached freezing. Which of the following areas may be slippery?

A shaded area

All of the above

A bridge

A wet-looking road

27 / 32

27.

What is the penalty for driving a commercial motor vehicle (CMV) without a CDL?

A fine of up to $2,000 and mandatory jail time

A fine of up to $5,000 or possible jail time

A fine of at least $5,000 and possible jail time

A fine of up to $1,000 and possible jail time

28 / 32

28. How many tie-downs are required for a 20-foot load?

29 / 32

29.

Which of the following are safe ways to communicate with others?

Flashing your headlights at night when you're about to pass

Tapping your horn when it's legal and you're about to pass

All of the above

Flashing your brake lights when you're about to slow down

30 / 32

30. Which of the following should you check during your trip?

All of the above

Cargo covers

Mirrors

Pressure gauges

31 / 32

31. How do you test a vehicle's hydraulic brakes for leaks?

Pump the brakes 3 times. Then apply firm pressure for 5 seconds.

Pump the brakes 3 times. Then apply firm pressure for 10 seconds.

Pump the brakes 5 times. Then apply firm pressure for 3 seconds.

Apply firm pressure for 5 seconds. Then pump the brakes 3 times.

32 / 32

32. The most important hand signal you should agree on with a helper is

“Turn up the music.”

“Stop.”

“Go.”

“Faster.”

Your score is

The average score is 33%

ONLINE CDL SCHOOL

How to use the result

Butler Transport Inc

Waller Truck Co

Fraley and Shilling