Whats Covered on the CDL General Knowledge Exam
Oct 25, 2025 · 2 min read
What Is the CDL General Knowledge Exam?
The Commercial Driver's License (CDL) General Knowledge exam is a critical first step for anyone looking to operate commercial motor vehicles (CMVs) professionally. Whether you're aiming to drive a tractor-trailer, a bus, or a delivery truck, passing this exam is essential.
The CDL General Knowledge exam is required for all CDL applicants and covers a broad range of topics related to the safe operation of commercial vehicles. The test typically consists of 50 multiple-choice questions and requires a score of at least 80% to pass.
Key CDL Exam Topics: Vehicle Inspection and Safe Driving
Vehicle inspection is one of the most important and heavily tested topics on the CDL General Knowledge exam. You will be expected to know how to conduct a thorough pre-trip inspection and identify any safety issues before operating the vehicle.
Safe driving practices form another major section of the exam. Topics include maintaining safe following distances, understanding speed limits for commercial vehicles, managing adverse weather conditions, and handling vehicle emergencies.
Cargo Transport, Air Brakes, and Federal Regulations
If you plan to haul cargo, the exam will cover topics such as cargo securement methods, proper weight distribution, hazardous materials basics, and required documentation for cargo transport.
If you plan to operate a vehicle equipped with air brakes, this topic is critical. Even though the Air Brakes section may be part of a separate endorsement, some general knowledge questions may touch on this system.
The exam also tests your knowledge of federal and state regulations governing commercial driving. Staying compliant with these regulations is vital for keeping your CDL in good standing.
How to Prepare for the CDL General Knowledge Exam
The CDL General Knowledge exam is the foundation for your commercial driving career. By focusing on the key CDL exam topics — including vehicle inspection, safe driving, cargo transport, and regulations — you can build the knowledge and skills needed to succeed.
- Create a realistic study schedule that fits around work hours
- Use your state's CDL manual as your primary study resource
- Take practice tests to simulate the exam environment
- Focus on understanding concepts, not just memorizing facts