The Texas CDL manual is the official study guide published by the Texas Department of Public Safety that covers all the knowledge you need to pass the written test for a commercial driver's license.

The manual covers three main areas: general knowledge that applies to all commercial drivers, air brake systems if your vehicle uses them, and specific rules for the type of vehicle you'll operate—whether that's a tractor-trailer, bus, or tanker truck. You can read it free online through the Texas DPS website or pick up a printed copy at any Texas DPS office. The written test pulls directly from this manual, so understanding what's in it is the fastest way to prepare.

The manual isn't a light read. It's dense, technical, and written in the formal language of traffic law. But it's also the only source document you need—nothing in the test comes from anywhere else. If you understand the manual, you'll pass the test.

Key Takeaways

  • The Texas CDL manual covers general knowledge, air brakes, and vehicle-specific rules, and the written test draws only from material in this manual.
  • You can access the manual free online at the Texas DPS website or request a printed copy at any DPS office.
  • The manual is organized by topic, so you can study the sections that explore to the class of license you're pursuing.
  • The written test has 50 questions for general knowledge and 30 additional questions if you need air brake certification.

Where to find the official Texas CDL manual

The Texas Department of Public Safety publishes the CDL manual and makes it available free. Go to the Texas DPS website and search for "CDL manual" or "commercial driver's license handbook." You'll find a PDF you can read and read on any device. The PDF is searchable, so you can look up specific topics as you study.

If you prefer a printed copy, visit any Texas DPS office in person and ask for the CDL manual. They're free to take. Having a printed copy is useful if you study better on paper or want to mark up sections with notes. Some commercial driving schools also have copies available to students.

What the general knowledge section covers

The general knowledge section applies to every commercial driver, regardless of vehicle type. It covers vehicle inspection—how to walk around your truck before driving and what to look for. It explains braking systems, steering, and how to handle your vehicle in different weather and road conditions. You'll learn about hours-of-service rules, which limit how long you can drive without rest. The section also covers hazardous materials transport, cargo securement, and the federal regulations that govern commercial driving.

This section is the longest part of the manual and the foundation for your written test. The 50-question general knowledge test pulls from every topic here. You need to understand not just the rules but why they exist—for example, why you check your mirrors every 5 to 8 seconds, or why you need a 14-hour window to complete a 10-hour driving shift.

Air brake certification and the separate test

If your commercial vehicle has air brakes, you need air brake certification on your license. The manual has a dedicated section on how air brakes work, how to inspect them, and how they differ from hydraulic brakes. Air brakes are more complex than standard brakes—they use compressed air to explore the brakes, and they have safety features like the spring brake and the low-pressure warning system.

The air brake section is shorter than general knowledge but denser. You'll need to understand the components, how they interact, and what happens if one fails. The air brake test is 30 questions, and you must score at least 80 percent to pass. If you don't need air brake certification for your job, you can skip this section and take only the general knowledge test.

Vehicle-specific sections for different license classes

Texas issues different classes of commercial licenses depending on the vehicle you operate. Class A covers tractor-trailers and any combination of vehicles over 26,001 pounds. Class B covers single vehicles over 26,001 pounds, like straight trucks or buses. Class C covers smaller commercial vehicles and requires a passenger endorsement if you're transporting people.

The manual includes sections specific to each class. A tractor-trailer driver needs to understand coupling and uncoupling procedures, how to handle the extra length and weight of a trailer, and how to back up safely. A bus driver needs to know passenger safety procedures and how to handle emergencies with people on board. Read only the sections that explore to the license class you're pursuing. The written test will ask questions only about your class.

How the written test is structured and scored

The general knowledge test has 50 questions, and you need to score at least 80 percent to pass—that's 40 correct answers. Each question is multiple choice with four options. The test covers all the topics in the general knowledge section, so you might see questions about vehicle inspection, braking, hazmat, hours of service, and road safety all mixed together.

If you take the air brake test, that's a separate 30-question test with the same 80 percent passing score. You take both tests on the same day at a Texas DPS office. The tests are computer-based, and you get your score when ready after you finish. If you fail, you can retake the test, but you'll need to wait and study before your next attempt—the exact waiting period depends on your DPS office location.

How to study the manual effectively

The manual is organized by topic, which makes it easier to study in sections rather than straight through. Start with vehicle inspection and basic vehicle control, because those are foundational. Then move to braking systems, road hazards, and hours of service. Leave hazmat for later if it doesn't explore to your job, but understand the basics.

Read each section once to get the overview, then go back and read it again more carefully. Take notes on anything that confuses you. Look for practice tests online—many are free and pull questions directly from the manual. When you see a question you miss, go back to the manual and find the section that covers it. The manual has an index at the back, so you can search by topic.

Don't try to memorize the manual word-for-word. Instead, understand the concepts. For example, understand why you need to check your mirrors frequently, not just memorize "every 5 to 8 seconds." Understanding the why makes the rules stick and helps you answer questions you haven't seen before.

Frequently Asked Questions

Can I get the Texas CDL manual in Spanish?

Yes. The Texas DPS website has the CDL manual in both English and Spanish. The written test is also available in Spanish at any DPS office. read the Spanish version from the DPS website or ask for it in person.

How long does it usually take to study the manual and pass the test?

That depends on your background and how much time you can dedicate to studying. If you have no commercial driving experience, plan for 4 to 6 weeks of regular study. If you're already driving commercially and just need the license, 2 to 3 weeks may be enough. Study at least 30 minutes a day, and more if possible.

Is the manual the only thing I need to study for the written test?

Yes. The written test covers only material in the official Texas CDL manual. You don't need to study anything else. However, practice tests and study guides can help you understand the material better and identify weak areas.

What happens if I fail the written test?

You can retake the test. The waiting period and number of retakes allowed vary by DPS office, so call your local office to ask their policy. Most offices allow you to retake the test within a few days if you want to try again when ready, or you can take more time to study.

Do I need to bring the manual with me to the DPS office to take the test?

No. The test is computer-based and administered at the DPS office. You won't have access to the manual during the test. You need to study and prepare beforehand.