Apr 24 / Amir

How to Study for the CDL Exam: A Complete Guide

How to Study for the CDL Exam: A Complete Guide

Earning a Commercial Driver’s License (CDL) opens the door to a stable and high-paying career in trucking, bus driving, and commercial transport. But before you can get behind the wheel of a commercial vehicle, you’ll need to pass the CDL exam and that means studying smart.
Whether you’re applying for a Class A, B, or C license, the CDL exam covers critical safety knowledge, driving laws, and vehicle operation skills. With the right study plan and tools, you can pass your test faster and with more confidence.
At OnlineTrafficSafety.com, we specialize in online CDL prep courses designed to make studying convenient, affordable, and effective. In this guide, we’ll walk you through exactly how to prepare for your CDL exam the right way.

1. Understand What the CDL Exam Includes

Before you crack open the books or sign up for courses, it’s important to understand the structure of the CDL exam. The exam has two key parts:

Written Knowledge Tests

To get your Commercial Learner’s Permit (CLP), you’ll need to pass several written knowledge tests. These may include:
  • General Knowledge (mandatory for all CDL applicants)
  • Combination Vehicles (for Class A)
  • Air Brakes (if you’ll be driving air brake-equipped vehicles)
  • Endorsement Tests (HazMat, Tanker, Passenger, Doubles/Triples, etc.)
Each test includes multiple-choice questions that assess your understanding of safety procedures, laws, vehicle mechanics, and best driving practices.

Skills Test

After you get your CLP and complete entry-level driver training, you’ll need to pass the CDL Skills Test, which includes:
  • Pre-trip inspection: Demonstrating your knowledge of safety checks.
  • Basic control: Showing you can maneuver the vehicle (backing, turning, parking).
  • Road test: Driving in real-world conditions with an examiner.
In this blog, we’re focusing on the written portion, which you must pass first to get your CLP.

2. Start With the CDL Manual

Every state provides a CDL Driver’s Manual, typically through the Department of Motor Vehicles (DMV). This manual is your official study guide and contains everything that will be tested on your written exams.
Here’s how to study it effectively:
  • Download the manual from your state DMV website (it’s free).
  • Focus on sections related to your license class and endorsements.
  • Highlight or take notes on key rules, definitions, and safety procedures.
  • Use it alongside practice tests to reinforce your learning.
You can also find state-specific guidance built into our online CDL prep courses, which are structured to help you retain the most test-relevant material quickly.

3. Use Online CDL Courses to Save Time

Studying the CDL manual alone can feel overwhelming and time-consuming. That’s why many drivers turn to online CDL courses that break the information down into manageable lessons with interactive quizzes.
Here’s why using an online course from OnlineTrafficSafety.com gives you an advantage:
  • FMCSA-compliant CDL theory training
  • Covers General Knowledge, Air Brakes, Combination Vehicles, and endorsements
  • Access the course on any device — phone, tablet, or desktop
  • Includes unlimited practice exams to boost confidence
  • Track your progress automatically and know when you’re test-ready
Online learning allows you to study at your own pace, whenever and wherever it’s convenient for you whether it’s during a lunch break or at night after work.

4. Take Practice Tests Repeatedly

One of the most proven ways to pass the CDL exam is to take practice tests frequently.
Here’s why practice tests matter:
  • They simulate the real test format so you know what to expect.
  • They reveal your weak areas so you can focus your studying.
  • They help build confidence and reduce anxiety on test day.
Our CDL exam prep program includes state-specific practice tests that closely mirror the actual questions used by DMVs. These tests cover all key areas and offer explanations for each answer, helping you understand not just what is correct, but why.
Take each practice test multiple times and aim to consistently score 90 percent or higher before scheduling your DMV exam.

5. Learn by Category, Not Just Chronologically

Instead of reading the CDL manual cover-to-cover, group your studying by topic area:
  • Vehicle Inspection: Know every component and how to check it
  • Driving Techniques: Understand speed management, space control, braking
  • Hazards and Emergencies: Learn how to handle skids, fires, spills, and more
  • Transporting Cargo or Passengers: Focus on your specific class/endorsement
  • Regulations: Know Hours of Service, alcohol limits, record-keeping
This method allows you to go deeper into each subject, helping you retain information longer and perform better on multi-question categories during the test.

6. Study a Little Every Day

Consistency beats cramming. Aim for short, focused study sessions every day rather than long, infrequent ones.
Here’s a sample schedule:
  • Monday: General knowledge – vehicle control and inspections
  • Tuesday: Air brakes and braking systems
  • Wednesday: Combination vehicles (if applicable)
  • Thursday: Emergency procedures and hazardous conditions
  • Friday: Endorsements (HazMat, Passenger, etc.)
  • Saturday: Take full-length practice test
  • Sunday: Review weak areas
Our online CDL course is built to support this style of learning, with clear progress tracking and the ability to pause and resume lessons anytime.

7. Focus on Endorsements if Required

If your job will involve hauling hazardous materials, driving a tanker, or transporting passengers, you’ll need additional endorsement tests.
Popular CDL endorsements include:
  • HazMat (H): Requires TSA clearance and a separate written test.
  • Tanker (N): For hauling liquids in bulk.
  • Passenger (P): For driving buses or vans with 16+ passengers.
  • School Bus (S): For driving school buses (must also pass a background check).
Start studying for these at the same time as your general knowledge prep. Many drivers wait too long and get delayed later when applying for specific jobs.

8. Track Your Progress and Readiness

One of the most overlooked parts of studying is knowing when you're ready to take the real exam.
At OnlineTrafficSafety.com, our CDL prep platform tracks:
  • Your lesson completion
  • Your quiz and test scores
  • Your weak areas that need review
Once you’re scoring above 85 to 90 percent on practice tests consistently, you’re likely ready to pass the DMV exam. At that point, you can schedule your written test and move toward the hands-on training phase with confidence.

9. Create a Quiet, Distraction-Free Study Space

Learning to drive a commercial vehicle is serious business, and it requires focus. Create a quiet, clean study area where you can learn without distraction.
If you’re using our online CDL course, you can access the platform on your phone, but avoid multitasking with TV, social media, or other distractions.
Instead:
  • Turn off notifications
  • Set a timer for 30 to 45 minutes of uninterrupted study
  • Take short breaks to avoid burnout
Treat your CDL prep like a job because it will lead you directly to one.

10. Use Support When You Need It

If you're struggling with a specific topic or unsure about the testing process, do not hesitate to ask for help.
OnlineTrafficSafety.com offers support resources, and our content is built by CDL experts to help explain even complex topics in simple, clear language.
You can also reach out to local driving schools for help with scheduling behind-the-wheel training after you’ve passed the written exam.

Final Thoughts

Studying for the CDL exam may seem challenging at first, but with the right tools and a clear strategy, it becomes entirely manageable.
Start with your CDL manual, then build a consistent study schedule using proven resources like our online CDL prep course. Use practice tests, study by category, track your progress, and prepare for any needed endorsements upfront.
When you take your learning seriously and study every day, you’ll pass the CDL exam with confidence — and get one step closer to a stable, high-paying commercial driving career.
Ready to start studying the smart way?
 Visit OnlineTrafficSafety.com to access your CDL course today and take the first step toward your new career.