The CDL test has two parts: a written knowledge exam and a driving skills test

A Commercial Driver's License (CDL) requires you to pass both a written test and a practical driving exam. The written test covers traffic laws, vehicle operation, and safety rules specific to commercial trucks. The driving test happens in an actual truck and measures whether you can operate it safely on the road. You must pass the written portion before you can take the driving test, and you need both to get your CDL.

Most states require you to hold a valid regular driver's license before you start CDL training. Some states let you test for a CDL permit first—a written-only credential that lets you practice driving a commercial truck with a licensed CDL holder in the passenger seat. This permit is optional but useful if you want supervised practice before the full exam.

Key Takeaways

  • The written test covers vehicle inspection, safe driving practices, and commercial vehicle laws; you must score at least 80 percent on most state exams to pass.
  • The driving test includes a vehicle inspection component, a basic control test in a closed course, and a road test in real traffic—all in the same vehicle you will operate professionally.
  • CDL training programs range from three weeks to several months and teach both the knowledge and hands-on skills; some are offered through community colleges or private truck driving schools.
  • You can study for the written test using your state's CDL manual, practice tests, and study guides; the manual is free and covers everything on the exam.
  • Scheduling the driving test requires passing the written test first and booking an appointment with your state's Department of Motor Vehicles or an approved testing facility.

What the written knowledge test covers

The written test is divided into sections, and you must pass each one. The general knowledge section covers basic traffic laws, vehicle operation, and safe driving practices. If you plan to haul hazardous materials, you take an additional hazmat section. If you will operate a vehicle with air brakes, you take an air brakes section. Some drivers need multiple endorsements depending on what they will carry or drive.

Each section typically has 30 to 50 questions, and you usually need to score 80 percent or higher to pass. The test is multiple choice and covers topics like how to inspect a vehicle before driving, how to handle skids, what to do in an emergency, weight and load limits, and hours-of-service rules. Your state's CDL manual contains all the material tested; it is free and available online or at your local DMV office.

You can take the written test at your state's DMV or at an approved third-party testing facility. Some states allow computer-based testing; others use paper tests. The test usually takes one to two hours. If you fail, you can retake it after a waiting period—typically a few days to a week, depending on your state.

How the driving skills test is structured

The driving test has three parts, all conducted in the same commercial vehicle. The first part is the vehicle inspection test, where you walk around the truck and point out safety features and potential problems. The examiner asks you to identify lights, brakes, tires, mirrors, and other components and explain what you are checking for. This part takes about 15 minutes and tests whether you know how to inspect a vehicle before operating it.

The second part is the basic control test, conducted in a closed course or parking lot. You perform maneuvers like backing straight, backing at an angle, parking between cones, and turning in a confined space. These exercises show whether you can handle the truck's size and weight in a controlled environment. This part usually takes 10 to 15 minutes.

The third part is the road test, where you drive the truck in real traffic for 20 to 30 minutes. The examiner watches how you accelerate, brake, turn, merge, and respond to other vehicles and road conditions. You will drive on highways, city streets, and residential roads. The examiner is looking for smooth, safe operation and correct use of mirrors, signals, and brakes.

How to prepare for the written test

Start by reading your state's CDL manual from beginning to end. The manual is organized by topic and covers everything the test will ask. After reading, use practice tests to identify weak areas. Many states offer free practice tests online; others are available through study websites and apps. Take practice tests under timed conditions to get used to the pace.

Focus extra time on sections you find difficult. Common trouble spots include air brake systems, hazmat rules, and hours-of-service regulations. If you are taking a hazmat or air brakes endorsement, those sections require separate study. Some people find it helpful to join a study group or take a CDL prep course, though these are not required.

On test day, bring a valid ID and any documents your state requires. Arrive early so you are not rushed. Read each question carefully; some are worded in ways that can be confusing if you skim. If you are unsure about an answer, mark it and come back to it after you finish the rest.

How to prepare for the driving test

The best preparation is hands-on practice in a commercial truck. A CDL training program provides this; most programs include classroom instruction, simulator practice, and at least 100 to 200 hours of actual driving with an instructor. The instructor teaches you how to handle the truck's size, how to use the mirrors effectively, how to brake smoothly, and how to navigate different road conditions.

If you are practicing outside a formal program, you need a licensed CDL holder in the passenger seat. Practice backing, turning, and parking in various scenarios. Practice on highways, in city traffic, and on rural roads. The more varied your experience, the more confident you will be on test day.

Before the test, inspect the truck you will be tested in if possible. Learn where the controls are, how the mirrors are adjusted, and how the brakes feel. On test day, arrive early, get comfortable in the cab, and adjust the seat and mirrors. During the test, drive smoothly, use your mirrors constantly, signal every turn and lane change, and follow all traffic laws. If you make a mistake, stay calm and keep driving safely.

CDL training programs and how they work

A CDL training program teaches you the knowledge and skills needed to pass both tests. Programs vary in length—some are four weeks, others are eight weeks or longer. Full-time programs meet daily; part-time programs meet evenings or weekends. Community colleges, private truck driving schools, and some employers offer CDL training.

A typical program includes classroom instruction on traffic laws and vehicle systems, behind-the-wheel training with a professional instructor, and practice tests. Some programs include job placement help after you pass your CDL test. Costs vary widely, from a few hundred dollars to several thousand, depending on the program length and location.

If you cannot afford a program, some states offer funding through workforce development agencies or community colleges. Some employers will pay for training if you agree to work for them after you get your license. Check with your state's workforce agency or local community college to learn what options are available in your area.

What happens after you pass both tests

Once you pass the written test and the driving test, your state's DMV will issue your CDL. The license is valid for four or eight years, depending on your state. You will need to renew it before it expires, which usually involves passing a written test again and paying a renewal fee.

Your CDL will show what classes of vehicles you can drive and what endorsements you have. A Class A CDL lets you drive the largest trucks; a Class B CDL covers smaller commercial vehicles. Endorsements like hazmat or passenger allow you to haul specific cargo or carry passengers. If you want to add endorsements later, you take additional written tests and, in some cases, additional driving tests.

Frequently Asked Questions

Can I take the written test and driving test on the same day?

No. You must pass the written test first, then schedule the driving test for a later date. Most states require at least a few days between the two tests. Some states have a waiting period of one to two weeks.

What happens if I fail the driving test?

You can retake it after a waiting period, usually one to two weeks. You do not have to retake the written test unless your state requires it. Most people pass on the second or third attempt. Each attempt costs a testing fee.

Do I need to attend a CDL training program, or can I study on my own?

You can study the written material on your own using your state's CDL manual and practice tests. However, the driving test requires hands-on practice in a commercial truck with a licensed CDL holder supervising. Most people find a formal training program helpful because it provides structured instruction and professional feedback.

What is the difference between a CDL permit and a CDL?

A CDL permit is a written-only credential that lets you practice driving a commercial truck with a licensed CDL holder in the passenger seat. A CDL is the full license that lets you drive commercially on your own. Not all states offer permits; check with your state's DMV.

How much does it cost to get a CDL?

Testing fees vary by state but usually range from $50 to $200 for the written test and $100 to $300 for the driving test. CDL training programs cost anywhere from $500 to $5,000 depending on length and location. Some employers or workforce programs cover these costs.