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

What will help a drunk sober up?

Fresh air

A glass of water

Time

Coffee

2 / 32

2. Total stopping distance equals

Perception distance + reaction distance + braking distance.

Perception distance + reaction distance.

Reaction distance + braking distance + signal distance.

Reaction distance + braking distance.

3 / 32

3. 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.

All of the above can work.

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.

4 / 32

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

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

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.

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.

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

5 / 32

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

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

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

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

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

6 / 32

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

Gasoline

Grease

Electrical

Wood

7 / 32

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

Ten years minimum

Five years minimum

Three years minimum

Life

8 / 32

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

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

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

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

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

9 / 32

9. 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.

10 / 32

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

To check the cleanliness of your vehicle

Employer liability

To make sure your paint is not chipped

Safety

11 / 32

11.

Letting the air out of hot tires

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

will have no effect at all.

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

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

12 / 32

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

13 / 32

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

When your engine speed increases

If you're going down a steep downgrade

If you start to get drowsy

If you feel you're driving too fast

14 / 32

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

Pitman arm

Lock ring

All of the above

Bearing plate

15 / 32

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

The level of anger

All of the above

The outcome of the situation

Whether it's intentional

16 / 32

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

10 seconds

More than 30 seconds

14 seconds

More than 15 seconds

17 / 32

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

1 inch.

8/32 inch.

4/32 inch.

2/32 inch.

18 / 32

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

Releasing the clutch

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

Releasing the clutch and pressing the accelerator at the same time

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

19 / 32

19. 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.

20 / 32

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

someone could start and move the truck.

someone could steal the truck.

it could damage the starting mechanism.

any of the above could occur.

21 / 32

21.

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

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

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

All of the above

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

22 / 32

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

All of the above

Pressure gauges

Cargo covers

Mirrors

23 / 32

23. 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.

avoid using your cell phone until you reach your destination.

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

24 / 32

24. What is a common cause of tire fires?

Underinflated tires

Overinflated tires

Cold tires

All of the above

25 / 32

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

Just turn your head and look at your blind spots.

Stop every 50 miles and look around.

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

Check your reflection in other vehicles.

26 / 32

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

Talking on a cell phone

Traveling at 15 mph or more above the posted speed limit

All of the above

Playing music too loudly

27 / 32

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

increase your stopping distance.

keep your wheels from locking when you brake hard.

let you drive faster.

increase your vehicle's stopping power.

28 / 32

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

Starting up a hill and entering a curve

Starting up a hill and finishing a curve

Starting down a hill and entering a curve

Starting down a hill and finishing a curve

29 / 32

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

30 / 32

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

A shaded area

All of the above

A wet-looking road

A bridge

31 / 32

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

“Go.”

“Stop.”

“Faster.”

“Turn up the music.”

32 / 32

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

ignore rude gestures and refuse to react negatively.

do all of the above.

avoid eye contact.

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

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