This CDL general knowledge practice test will examine your knowledge of general trucking, safe transportation of cargo, safe driving, and the correct way to perform a pre-trip vehicle inspection. In order to receive your CDL, it is required that you pass the state’s official CDL General Knowledge exam.
If lock nuts on your wheels have streaks of rust, this may indicate...?

Question 1 of 30

Air pressure for your brakes should build from 50 to 90 psi within what time?

Question 2 of 30

Side marker reflectors which are not at the rear of the vehicle must be what color?

Question 3 of 30

If a yellow light on the left rear of the trailer stays on when you switch the engine on, this means...?

Question 4 of 30

If you are transporting a cargo you must inspect its securement within what distance of starting a trip?

Question 5 of 30

As you check your signal lights, you should...?

Question 6 of 30

Side marker lights must be what color at the rear of the vehicle?

Question 7 of 30

All tires other than the front tires of a commercial vehicle must have a minimum tread depth of...?

Question 8 of 30

The most important reason for inspecting your vehicle before traveling is...?

Question 9 of 30

Why should you look under your vehicle at the beginning of your pretrip inspection?

Question 10 of 30

Wheels or rims are unsafe if they have been welded...?

Question 11 of 30

As part of your safety equipment, your vehicle should have how many red reflective triangles?

Question 12 of 30

After your first in trip inspection of the securement of your cargo, you must make regular additional inspections...?

Question 13 of 30

Front facing turn signals must be what color?

Question 14 of 30

What is the main problem which a broken exhaust system can cause?

Question 15 of 30

When you are on the road, you must fasten your seatbelt...?

Question 16 of 30

Which of these is permitted for use on the front wheels of the bus?

Question 17 of 30

Rear turn signals should be which of these colors?

Question 18 of 30

Before starting the engine on a manual vehicle you should make sure your gearshift is in...?

Question 19 of 30

On a 20 inch steering wheel, there should not be more than how much play?

Question 20 of 30

To check the stopping action of your service brakes, you should test them at about...?

Question 21 of 30

What paperwork should you check before beginning your pretrip inspection?

Question 22 of 30

A vehicle must be placed out of service if what fraction of the leaves in any spring assembly on the suspension are broken?

Question 23 of 30

If your oil pressure is below the indicated limit, you should...?

Question 24 of 30

Every major groove on the front tires of a commercial vehicle must have a tread depth of at least?

Question 25 of 30

Which of these senses should be used during a trip to check for problems?

Question 26 of 30

When checking the steering system, it must be tested...?

Question 27 of 30

If your vehicle has hydraulic brakes, you should pump the brake pedal three times and then apply firm pressure for five seconds. The pedal should...?

Question 28 of 30

The second step of a pretrip inspection should be to check...?

Question 29 of 30

What is the proper color at the front of a vehicle for parking, clearance and identification lights?

Question 30 of 30



Why Take This CDL General Knowledge Practice Test?

You will be required to take a written knowledge test (try our CDL general knowledge practice test). Once you pass this test, you will be required to drive with another CDL licensed driver and practice driving on the road for at least 14 days.

The cost of getting your CDL will vary depending on the state you live in. On average, obtaining a learner’s permit will cost around $25. To get your full CDL license, fees will range from $50 to $200. While this might seem like a lot of money, the income you will receive in the future will make it worth the money.

There are three types of CDL classes that determine the type of vehicle you may drive and how much you may tow. A Class A CDL class allows you to operate a vehicle with a GCWR of 26,001 if the vehicle you tow weighs more than 10,000 and a Class B CDL allows you to operate a vehicle with a GVWR of 26,001 or more pounds or operate any vehicle towing another vehicle that weighs less than 10,000 GVWR. With a Class C CDL, you can operate a Class C vehicle that transports hazardous materials.