What Is The CDL Written (General Knowledge) Test?

The CDL written test is called the general knowledge test. The general knowledge test is the first of several tests that you will have to complete in order to get your cdl.

This test is important because after passing it you will be issued a commercial learner permit (CLP).

If you are serious about becoming a trucker then you need to invest in yourself so that you can pass all the written tests.

To make sure you pass the CDL General Knowledge test the best practice tests are these. The best thing about them is that there is no BS. You get access to the full test and can take it over and over.

The CLP (permit) allows you to start your cdl training with an actual truck. The CLP is the same as the drivers license permit you received before you started driving a car.

If you are getting your CDL then this is step 1. You need to be prepared for it, don’t expect
to pass the test with little or no studying. The test can be surprisingly challenging for some people and will require significant studying.

Besides, it’s a good habit to start studying for exams because your path to getting a CDL is going to be loaded with all kinds of tests.

In this article I’m going to answer all your questions about the CDL written test (general knowledge test) so that you know what to expect and can pass it on your first try.

Who Has To Take The General Knowledge Test?

Anyone that is seeking a Class A, B, or C CDL has to pass the general knowledge test.

If there is a chance you are going to be driving a commercial vehicle with air brakes you will also need to take the air brakes test along with the general knowledge.Anyone seeking a Class A CDL will have to take the air brakes test.

Also, if you are seeking a Class A CDL you will need to take the combination vehicle test as well. This allows you to drive different combinations of tractor trailers.

Which Other Tests Should You Take At The Same Time As The General Knowledge Test?

You might have take 2 other tests, the air brakes and combination vehicle test (if you are seeking a Class A CDL).

Why should you take the air brakes test too? You have to take and pass the general knowledge test and air brakes test so that you can get your CLP and start driving a commercial vehicle with air brakes.

Not all commercial vehicles have air brakes though. If you are going to be driving a passenger bus, a large tractor trailer, or some larger box trucks you will need to pass the air brakes test in order to drive them.

Why should you take the combination test too? The combinations vehicle test is required by anyone trying to get a Class A cdl. If you are going to be driving any kind of tractor trailer you’ll need to pass this test too.

It’s best to take all the tests at once so you are all set to start training/driving. If you don’t pass the combination vehicle test you won’t be able to drive a tractor with a trailer even if you pass the general knowledge test.

How Many Questions Are On The General Knowledge Test?

In most states the general knowledge test has 50 questions on it. Some states may have a few more but I haven’t heard of a particular state that has more than 50 as of the year this was written (2018). You usually are given a time limit of 60 minutes to answer the questions.

All of the questions that are on it are multiple choice questions just like the ones you remember taking high school.

Many of the questions on it some people would consider “common sense” questions. Don’t take this for granted though. A lot of the questions do require some significant studying in order to pass.

Listen, you have to pass this test in order to get your CDL, so take it seriously!

Where Can You Take The General Knowledge Test?

To take the test you need to contact your local DMV (Department of Motor Vehicles) and make sure that they administer it. That’s it, you go the DMV and take it in person.

What Percent Do You Need To Pass The General Knowledge Test?

To pass the test you need to answer 80 percent of the questions correctly. If you are taking the air brakes test and combination vehicle test (you should) at the same time it is possible to score less than 80 percent on the air brakes test and still get your permit.

The only thing is that it will be noted on your permit (CLP) as a restriction. This means you won’t be able to practice driving a commercial vehicle with air brakes and is a semi trailer. Basically, you will have a permit but won’t be able to drive anything.

If you are planning on driving a semi trailer you won’t be able to until you pass the air brakes and combination test as well as the general knowledge.

How Hard Is It To Pass The Test?

It’s not that hard. Sure, you will have to do a little prep for the test (use the tools at the bottom of this article) but there is no reason why you can’t pass it on your first or second time.

Read and practice the multiple choice questions over and over until you are ready to go. Don’t overthink it, you got this!

One resource I could suggest is to try some free tests that you find throughout the internet.

However, if you want the guarantee that you will pass the test you have to go with a proven winner. The practice tests I recommend you make a small investment in are these tests.

The tests are awesome and you’ll get access to the written tests for the passenger endorsement, air brakes endorsement, combination vehicle endorsement, and a few more.

What Is The CDL Permit?

A CDL permit is called a commercial learner’s permit or CLP. This permit is what is issued to you after you pass the general knowledge test.

The CDL permit allows you, by law, to drive a commercial vehicle as long as someone that already has a valid CDL for the exact same vehicle is seated next to you in the vehicle at all times.

Think back to your driving permit you received before you got your actual driver’s license to drive a passenger car. As long as someone with a valid driver’s license for passenger cars was seated next to you it was okay, by law, to drive the car.

After you finished your training/class/drivers ed. you were able to get your driver’s license as long as you passed the written test and driving test.

The CDL permit is no different. With it you are taking your first step towards getting your CDL because now you can actually drive a commercial vehicle on public roads.

Regardless of the type of training you decide to go through you have to have a valid permit. To learn more about the permit you have to read this article.

How Long Is The Permit Valid For?

The permit is valid for 180 days after it was issued to you. This gives you plenty of time to complete your training.

What Are The Requirements To Take The General Knowledge Test?

  1. Have a valid driver’s license and be at least 18 years old in most states. If you want to drive across state lines you have to be 21 though.
  2. Depending on the state you will need 1 or 2 years driving experience.
  3. Provide proof of citizenship or lawful permanent residency. For this you will need a social security card, proof of social security number, birth certificate, or green card.

There are way more requirements that you need to meet in order to get your actual CDL but these 3 you will need in order to take the general knowledge test.

How To Study For The General Knowledge Test?

These days there are a lot of ways you can prepare for the general knowledge test.

Everything can be found online: testing apps, websites, videos, flashcards, pdf question and answers, books, and your state cdl manual.

I don’t want to mislead you, the questions that you answer on these practice tests are not the same exact questions you will see on the actual test. They are similar though and contain the same type of content. Don’t expect to go into the DMV and see questions that you have already answered.

CDL Prep Apps

There are a lot of apps out there that you can download onto your phone and use to help you pass the general knowledge test with ease. These apps are great because you can study from anywhere at any time.

Go through the questions on these apps before going to bed, while waiting to see a dentist, or sitting on a train or bus. Anywhere where you have a few minutes is a good time to practice.

You have several options for apps, here are some of the better ones that truckers that have already passed the test recommend for both Android and iOS phones:


CDL Practice Test: This app is by far one of the most used apps for the test. You really can’t go wrong with this one because it has an easy to use layout and the questions are very accurate to the type you will encounter on the actual test. This app has good reviews and high user ratings. Check it out yourself on Google Play by clicking here.

CDL Prep: Another highly rated app for passing the test. Has over 500 questions and the answers to questions will not always be in the same position. You can find it on Google Play by clicking here.

CDL Practice Test by Trucking Truth: Probably just as good, if not better, than the other two. This one by Trucking Truth has 565 multiple choice questions that are straight from CDL state manuals and previous tests. Get on Google Play by clicking here.

iOS (Apple)

CDL Practice Test: A highly rated app that will help you pass the test. It has over 1,200 questions and answers. Click here to get it for you Apple phone.

CDL Prep: This app has over 500 questions and answers. You are able to review answers and get instant feedback. To get it click here.


A second option for studying for the test is to use websites with sample questions. These are the same type of multiple choice questions as you would find on the apps except you don’t have to download anything to use these.

CDL Training Spot: I have a free list of questions that you can access here.

Trucking Truth: Easy to follow and is broken into 4 sections. Here is the link to the first section.

Driving Tests: Not much different than the other, a bunch of multiple choice questions for you to answer. Warning, this site has a ton of annoying ads on it. Go to it by clicking here.

Truckers Report: These guys have some nice practice tests, one of which is a timed and has 50 questions so that you really get a feel for how it is going to be when you take the test. You can go to their site by clicking here.

Flash Cards

Flashcards? Yes, flashcards are a great way to study for any type of test. Look online and you will find some pretty good flash cards for the general knowledge test too.

Here are a few that I recommend:

Quizlet: These flashcards are easy to use and aren’t cluttered with a ton of ads like some other sites. Remember, to flip over the flash card you have to click on the flash card. To go to the flashcards click here.

Cram.com: Not bad. A little confusing to use but once you get the hang of it they are pretty good too. Click here to see these.

YouTube Videos

You guessed it, YouTube. There are some decent videos on YouTube that you can use to study for the test. Some are better than others though. Below are two that are alright.

I’m not sure watching a YouTube video is the way to go but some people might like learning this way. Personally, I can’t stand watching these videos because you have to follow someone else as they talk about each question. So annoying.

PDF Questions And Answers

If you prefer paper copies of practice questions there are a lot of free downloadable questions you can use to study from. These are not actual copies of the test but the questions are similar to what you will find when you take the test. Each of these can be viewed as a PDF and printed.

General Knowledge Questions and Answers PDF 1

General Knowledge Questions and Answers PDF 2


There are a lot of books that you can also use to help you pass the test. Here are a few that are known to be effective that I found on Amazon. For not a lot of money you will have a study guide that you can use for the general knowledge test and the other tests you will eventually have to pass. Not a bad investment that you can use throughout your CDL training.

CDL Study Guide Book: A good book with pretty good reviews. One of the benefits of getting a book like this one is that you will have help with the other tests you are going to have to pass in order to get your CDL.

CDL Commercial Driver’s License Exam: Another good back that helps you prepare for more than just the general knowledge exam. This book (Amazon link) has it all in one book so you don’t have to look around the internet for everything.

State CDL Manual

Finally, the last way you can study for the general knowledge test is to use your CDL manual from the state you car going to get your CDL in.

I have a list of all of the manuals here for every state.

These are the 3 specific units that you have to study for the test which are the same for every state.

Section 1: Introduction: This section is has general information regarding the CDL. Topics include:
– Information about who must obtain a CDL
– Who is exempt from obtaining a CDL
– Endorsements
– Information about the CDL general knowledge exam and the skills/driving test
– Required documents, including the DOT Medical Exam Card
– Regulations and disqualifications
– Traffic violations in a personal vehicle
– Distracted driving
– Vehicle length, height, and weight restrictions
– Vehicle lighting

Section 2: Driving Safely: This section contains knowledge and safe driving information that every commercial vehicle driver should know. Topics include:
– Vehicle inspection
– Basic control of your vehicle
– Shifting gears
– Space management
– Winter driving
– Mountain driving
– Fires
– Driving emergencies
– Staying alert
– Accident procedures
– Braking distance
– Managing space
– Driving at night.
– What to do when you become sleepy

Section 3: Transporting Cargo Safely: In this section you will learn about the proper ways to load and secure cargo. Topics include:
– Inspecting cargo
– Cargo weight and balance
– Securing cargo
– Cargo needing special attention

*Section 5: Air Brakes: This section focuses on air brakes. If you intend to drive a commercial vehicle with air brakes you will need to study this section as well. Many Class A, B, and C vehicles utilize air brakes. Topics in this section include:
– Air brake system parts
– Dual air brake systems
– Inspecting air brakes
– Using air brakes

*Section 6: Combination Vehicles: This section is for drivers seeking a Class A CDL only. In this section you will learn about combination vehicles such as tractor-trailers, double trailers, triple trailers, and straight trucks with trailers. Section 7 of your state manual should also be reviewed if you are going to drive doubles or triples. Topics include:
– Driving combinations
– Combination vehicle air brakes
– Anti-lock brake systems
– Coupling and uncoupling
– Inspecting combinations

What Happens If You Don’t Pass Your First Time?

Don’t panic if you don’t pass the test on your first try. You are able to retake it as early as the following day. Most states will tell you that you can retake it 3 days in a row but if you still don’t pass it you have to wait 7 days to take it again.

If you can’t pass the test after 3 trials, you got problems. It’s not that hard.

Also, there is usually a retake fee that is only a few dollars.