CDL General Knowledge Practice Test 2023

CDL General Knowledge Practice Test 2023 Commercial Driver’s License Permit Test (CDL) in the USA: Try our free original CDL Knowledge Practice questions answers.

There is a total of 50 CDL General Knowledge Practice Question Answers with explanations.  You must pass the written test for the CDL that you need. In general, the CDL general knowledge test is required to be taken by all CDL applicants. The CDL test consists of 50 questions. To pass, you must correctly answer at least 40 questions (80%).

CDL General Knowledge Practice Test

Test Name CDL Practice Test 2023
Language English
License CDL (Class A, B, or C),
Total Questions 50 Knowledge Practice Test
Test For Commercial Driver License
Test Preparation Driving Knowledge
Country USA
Explanation Yes
0 votes, 0 avg

CDL General Knowledge Practice Test 1

1 / 50

You must turn your headlights on

2 / 50

If you are driving a 30 foot vehicle at 35 mph, how many seconds of following distance should you allow?

3 / 50

When driving in very hot weather, how often should you check the tires?

4 / 50

To determine how many seconds of following distance space you have, wait until a vehicle ahead passes a shadow on the road, a pavement marking, or some other clear landmark and then count the seconds until you reach the same spot and then double it.

5 / 50

To test hydraulic brakes for leaks, pump the pedal 3 times. Then apply firm pressure to the pedal and hold for 5 seconds. The pedal should move. If it doesn’t, there may be a leak or other problem.

6 / 50

Which of the following is NOT a suspension system defect?

7 / 50

Hydroplaning is more likely when tire pressure is high.

8 / 50

Which of the following factors should you take into consideration when determining a safe speed for going down a long, steep downgrade? Choose all that apply.

9 / 50

Driving with wet brakes can cause which of the following. Choose all that apply

10 / 50

Which of the following is a NOT a steering system part?

11 / 50

What is the minimum tread depth for tires?

12 / 50

When should a vehicle be inspected?

13 / 50

You should turn retarders on whenever the road is wet, icy, or snow covered.

14 / 50

You should shift your transmission to a low gear before starting a downgrade.

15 / 50

Empty trucks require greater stopping distance.

16 / 50

If you are being tailgated, what should you NOT do?

17 / 50

How far ahead should you look?

18 / 50

When doubling your speed, your braking distance is

19 / 50

When is it safe to remove the radiator cap?

20 / 50

The total stopping distance is reaction distance plus braking distance.

21 / 50

A thin layer of ice that is clear enough that you can see the road underneath is called

22 / 50

During very hot weather, you should let the air out the tires to prevent a blowout.

23 / 50

When water collects on the road and your tires lose contact with the road, this is called

24 / 50

If your brakes fail on a long downgrade, your best bet is to

25 / 50

When stopped on a hill, how do you prevent a vehicle from rolling back?

26 / 50

When backing a vehicle, you should back and turn towards what side?

27 / 50

What are the ways to know when to shift?

28 / 50

Stopping is not always the safest thing to do in an emergency.

29 / 50

When going down a long and/or steep downgrade, you should release the brakes after your speed has been reduced to:

30 / 50

Antifreeze is only necessary when driving in cold weather conditions

31 / 50

If weather conditions require the use of windshield wipers, you must also turn on your headlights.

32 / 50

What is the most important hand signal you can your helper should agree on?

33 / 50

The act of operating a motor vehicle in a selfish, bold, or pushy manner, without regard for the rights and safety of others is called:

34 / 50

When should a vehicle be inspected?

35 / 50

If an oncoming driver had drifted into your lane, what should you do?

36 / 50

Where should your reflectors be placed when stopped on a divided highway?

37 / 50

Wheel bearing seals should be checked for

38 / 50

Why is it important to use a helper when backing a vehicle?

39 / 50

During a vehicle inspection test, you should put the starter switch key in your pocket

40 / 50

What types of vehicles can get stuck on a railroad crossing? Select all that apply

41 / 50

For use as warning devices for parked vehicles, how many red reflective triangle should you carry?

42 / 50

If an aggressive driver is involved in an accident, you should stop immediately and help them; the same as you would for any other driver.

43 / 50

What are special conditions in which you should downshift?

44 / 50

How long does it take a typical tractor trailer unit to clear a double track?

45 / 50

A vehicle must be equipped with 3 kinds of emergency equipment. Which of the following is NOT one of them?

46 / 50

For vehicles with automatic transmissions, you can select a low range to get greater engine braking when going down grades.

47 / 50

If there is no white stop line painted on the pavement of a railroad crossing, vehicles that are required to stop must stop:

48 / 50

If you are driving a 30 foot vehicle at 55 mph, how many seconds of following distance should you allow?

49 / 50

Most people can tell when they are sleepy or about to fall asleep.

50 / 50

Drivers signaling a turn may be a hazard.

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The average score is 72%