Official CDL Test

🛑 Official CDL Knowledge Test

This is the real deal — the official CDL test section designed to help you prepare, prove your knowledge, and move forward with confidence. Whether you’re starting fresh or rebuilding your career, this test is your gateway to better opportunities.

📘 Covers core CDL topics with real-world relevance
📊 Your score helps match you with jobs and schools
🏆 Compete on the leaderboard and track your progress
🚀 Completing this test unlocks more personalized matches

Online CDL Test

This test evaluates your readiness to pass the official Commercial Driver’s License (CDL) exam, ensuring you have the knowledge needed to operate safely and legally as a professional truck driver. A solid understanding of CDL requirements helps drivers avoid violations, improve safety, and enhance career opportunities.

Topics Covered:

General knowledge, air brakes, and combination vehicle rules
Pre-trip inspection procedures and vehicle control fundamentals
Hazardous materials regulations and endorsements
Hours of Service (HOS) compliance and logbook requirements
Traffic laws, road safety, and defensive driving techniques

Passing this test demonstrates your ability to meet CDL standards and operate with professionalism and skill.

1 / 32

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

4/32 inch.

1 inch.

8/32 inch.

2/32 inch.

2 / 32

Letting the air out of hot tires

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.

will have no effect at all.

3 / 32

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

All of the above

Mirrors

Cargo covers

Pressure gauges

4 / 32

4. 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

5 / 32

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

10 seconds

More than 30 seconds

More than 15 seconds

14 seconds

6 / 32

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

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

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

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

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

7 / 32

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

8 / 32

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

Wood

Electrical

Grease

Gasoline

9 / 32

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

10 / 32

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

If you feel you're driving too fast

If you're going down a steep downgrade

When your engine speed increases

If you start to get drowsy

11 / 32

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

someone could steal the truck.

someone could start and move the truck.

any of the above could occur.

it could damage the starting mechanism.

12 / 32

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

Employer liability

To make sure your paint is not chipped

To check the cleanliness of your vehicle

Safety

13 / 32

13.

What will help a drunk sober up?

Coffee

Fresh air

Time

A glass of water

14 / 32

14. 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.

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

15 / 32

15. 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.

16 / 32

16. To maintain alertness during your trip, you should

get 8–9 hours of sleep beforehand.

avoid medications that cause drowsiness.

do all of the above.

schedule your trip for the daytime hours.

17 / 32

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

Releasing the clutch

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

Releasing the clutch and pressing the accelerator at the same time

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

18 / 32

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

“Faster.”

“Go.”

“Stop.”

“Turn up the music.”

19 / 32

19. 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

20 / 32

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

A shaded area

A wet-looking road

A bridge

All of the above

21 / 32

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

Pitman arm

Bearing plate

Lock ring

All of the above

22 / 32

22.

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

All of the above

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

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

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

23 / 32

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

Check your reflection in other vehicles.

Stop every 50 miles and look around.

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

Just turn your head and look at your blind spots.

24 / 32

24. Total stopping distance equals

Reaction distance + braking distance.

Perception distance + reaction distance.

Perception distance + reaction distance + braking distance.

Reaction distance + braking distance + signal distance.

25 / 32

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

keep your wheels from locking when you brake hard.

increase your vehicle's stopping power.

increase your stopping distance.

let you drive faster.

26 / 32

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

Playing music too loudly

Traveling at 15 mph or more above the posted speed limit

Talking on a cell phone

All of the above

27 / 32

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

Whether it's intentional

The outcome of the situation

The level of anger

All of the above

28 / 32

28.

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 $1,000 and 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

29 / 32

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

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

avoid using your cell phone until you reach your destination.

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

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

30 / 32

30. 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.

31 / 32

31. What is a common cause of tire fires?

Underinflated tires

Cold tires

All of the above

Overinflated tires

32 / 32

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

Yes, as long as there is no overflow.

Yes.

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

Your score is

The average score is 35%

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