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

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

2 / 50

When is it safe to remove the radiator cap?

3 / 50

How far ahead should you look?

4 / 50

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

5 / 50

Antifreeze is only necessary when driving in cold weather conditions

6 / 50

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

7 / 50

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

8 / 50

Hydroplaning is more likely when tire pressure is high.

9 / 50

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

10 / 50

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

11 / 50

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

12 / 50

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

13 / 50

Which of the following is NOT a suspension system defect?

14 / 50

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

15 / 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.

16 / 50

Drivers signaling a turn may be a hazard.

17 / 50

The total stopping distance is reaction distance plus braking distance.

18 / 50

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

19 / 50

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

20 / 50

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

21 / 50

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

22 / 50

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

23 / 50

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

24 / 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.

25 / 50

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

26 / 50

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

27 / 50

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

28 / 50

Wheel bearing seals should be checked for

29 / 50

You must turn your headlights on

30 / 50

What is the minimum tread depth for tires?

31 / 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.

32 / 50

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

33 / 50

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

34 / 50

Empty trucks require greater stopping distance.

35 / 50

When should a vehicle be inspected?

36 / 50

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

37 / 50

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

38 / 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.

39 / 50

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

40 / 50

What are the ways to know when to shift?

41 / 50

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

42 / 50

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

43 / 50

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

44 / 50

When should a vehicle be inspected?

45 / 50

When doubling your speed, your braking distance is

46 / 50

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

47 / 50

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

48 / 50

What are special conditions in which you should downshift?

49 / 50

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

50 / 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:

Your score is

The average score is 74%