CDL Study Guide

A career in the truck driving industry provides many rewards. From competitive pay to a flexible lifestyle, there’s something for everyone. However, if you want to reap these benefits, there are steps you’ll need to take. You’ll need to study and take a written test to obtain your Commercial Learner’s Permit before preparing for your Commercial Driver’s License (CDL) test. Truck driving schools like Driving Academy help students get the CDL driver training they need, both in the classroom and behind the wheel, helping them achieve their career goals. Our CDL study guide will help you better understand what you can expect from your written test.

Why Use a CDL Study Guide?

Before you can begin working with trucks on the road, you’ll need to show you’re proficient with the way that they work, their components, safety considerations, and more. Understanding these important aspects means you’re ready for the next step in your journey toward getting your CDL. While the complete list of requirements to get your CDL may vary by state, all states require you to pass the written test. Once passed, you’ll receive your Commercial Learner’s Permit (CLP). Let’s look more closely at what you’ll need to learn.

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General CDL Knowledge

The written test covers a wide range of topics. General knowledge helps explore these concepts thoroughly. First, you’ll need to learn what’s involved in a proper vehicle inspection. The 7-step method includes the following areas:

  1. Vehicle overview
  2. Checking the engine compartment
  3. Starting the engine and inspecting inside the cab
  4. Turning off the engine and checking the lights
  5. Performing a walking inspection
  6. Checking your signal lights
  7. Starting the engine and testing for hydraulic leaks

Aside from this initial inspection, you’ll also want to make sure to inspect the vehicle throughout your journey. You’ll need to learn proper safety techniques, including using your mirrors, backing up, and communicating with other drivers. This section also deals with important definitions you must understand, such as Gross Vehicle Weight Rating (GVWR) and Gross Combination Weight (GCW).

Air Brakes

Brakes are one of the most important components of any vehicle because they permit safe operation. Air brake systems are found in trucks, buses, tractor-trailers, and other large vehicles. In-depth knowledge of the air brake system will help you familiarize yourself with the parts, including the air compressor, brake pedal, safety valve, and alcohol evaporator. You’ll need to know how to properly inspect and operate them.

Combination Vehicles

Many CDL holders will operate combination vehicles. Combination vehicles refer to a tractor unit connected to one or more trailers. These vehicles require a fifth wheel or a converter dolly to bend when needed. Because of this addition, combination vehicles require extra knowledge and training, or safety could be a big concern. Learning how to make wide turns, travel over railroad tracks, and prevent rollovers are just a few of the concepts you’d need to study.

Doubles and Triples

Not all trucks are created equal, which is why there are special precautions and regulations when operating a vehicle that pulls a double or triple trailer. You’ll need to understand the legal restrictions for different trailer combinations in different states. You’ll also learn about coupling and uncoupling for double trailers and triple trailers, as each requires different steps. Because of these additional trailers, there are special steps to consider when doing a vehicle inspection.


Aside from your CDL, certain vehicles require additional endorsements on your license. This will allow you to pursue even more positions and work in different industries. These endorsements include:

Passenger Transport

There are special considerations when a driver is tasked with transporting passengers. To get your passenger endorsement (P), you’ll need to learn how to both operate a large vehicle and care for those you’re driving. While the exact regulations vary from state to state, passenger endorsements are generally required for vehicles that transport up to 15 people.

This endorsement allows you to drive city buses, airport shuttles, and other passenger vehicles. You’ll need to know additional inspection steps and how to operate emergency equipment, such as a fire extinguisher. Because all passengers have different needs, you’ll need to study how to handle wheelchairs, people with service animals, and other special situations.

Hazardous Materials

Certain materials can’t be transported by a driver unless they have a HazMat (H) endorsement on their CDL. Hazardous materials include explosives, toxic gases, radioactive materials, and more. This endorsement is generally viewed as the most difficult to obtain. Fortunately, a HazMat endorsement issued in one state is valid across the country. Having this endorsement will provide more opportunities and often comes with higher pay.

Some things you may need to learn for the test include:

  • Drivers of HazMat vehicles may be required to take special routes
  • Certain HazMat types may require you to obtain a special permit
  • Shippers determine whether a load is HazMat and provide placards
  • Drivers need to place a HazMat placard on the designated four sides of the vehicle

There are nine different classes for hazardous materials, and there are subdivisions of certain classes, so you’ll want to get acquainted with each before your test. It’s also important that the driver knows what’s being transported. If an accident occurs, emergency responders will need to know what chemicals or substances need to be contained.


A tanker endorsement (T) is designed for those looking to transport gas or other liquids. Because of the sheer weight of tankers, it requires special attention to detail on the part of the driver. Tanker endorsements are necessary if you’re driving over 119 gallons in a single tank or over 1,000 gallons overall.

When inspecting these vehicles, checking for leaks is vital. From the tank’s body to the piping and valves, any leak, no matter how small, is cause for concern. It’s also important to note these vehicles drive differently due to something called “surge.” Surge happens as the liquid moves within the tank. It can cause the vehicle to move forward when stopping too quickly or pull backward when accelerating too quickly.

Prepare for Your Test With Help From Driving Academy

At Driving Academy, our team of dedicated and experienced instructors can help you achieve your truck driving dreams. Aside from a CDL study guide, we offer full courses to prepare you for the written test and the road test that follows, or half courses, which are designed for those who already have their CDL permit and are ready to step inside one of our trucks. We can help you get your Class A CDL, Class B CDL, or Class B+P CDL. We even offer CDL practice tests to help you with your studies.

We have locations in Linden, Wayne, and Jackson Township, NJ, and in Gary, IN, and we have more locations set to open across the country. Our instructors have helped students from all around the country get the classroom knowledge and practical experience they need to pursue a successful career. If you’re interested in enrolling, want to start a franchise with us, or just have questions, contact us today.

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