The CDL test has two parts: a written knowledge exam and a behind-the-wheel driving test, both administered by your state's Department of Motor Vehicles

To drive a commercial truck, you need a Commercial Driver's License (CDL). Before you get one, you must pass two separate tests. The first is a written exam covering traffic laws, vehicle inspection, and safe driving practices specific to large trucks. The second is a practical driving test where an examiner watches you operate the vehicle and perform specific maneuvers. Both tests are run by your state's DMV or equivalent agency, not by a private training company.

You cannot take either test without first holding a valid regular driver's license. Most states also require you to pass a medical examination and obtain a Medical Certificate before you sit for the written test. The timeline from start to CDL varies widely depending on how much training you do beforehand and how quickly your state schedules exams.

Key Takeaways

  • The written test covers vehicle inspection, braking systems, cargo securement, and hazmat rules, and you must score at least 80 percent on your state's exam to pass.
  • The driving test lasts 30 to 45 minutes and includes a pre-trip inspection, basic control maneuvers, and on-road driving evaluated by a state examiner.
  • You must obtain a Medical Certificate from a certified medical examiner before taking either test, and this certificate is valid for two years.
  • Training programs vary in length from a few weeks to several months, and while not legally required, most people find formal training necessary to pass the driving test.
  • You can take the written test multiple times if you fail, but rules on retesting the driving portion vary by state.

The Written Knowledge Test: What It Covers

Your state's written CDL exam tests knowledge across several areas. The general knowledge section covers traffic laws, vehicle control, hazard perception, and safe driving practices. You will answer questions about braking distance, proper following distance, how to handle skids, and what to do in emergency situations. Most states require a score of at least 80 percent to pass.

Beyond general knowledge, you must also pass tests for the specific endorsements you need. If you want to haul hazardous materials, you take a hazmat endorsement test. If you want to carry passengers, you take a passenger endorsement test. If you want to haul double or triple trailers, you take a doubles/triples test. Each endorsement has its own written exam with its own passing score, usually also 80 percent.

The exam is administered on a computer at your DMV office. You typically have a set amount of time — often 60 to 90 minutes — to complete it. You can usually retake the written test if you fail, though your state may require you to wait a certain number of days between attempts. Check your state's specific rules before you schedule your first test.

The Driving Test: The Three-Part Evaluation

The practical driving test has three components, all conducted during a single appointment with a state examiner. The first part is the pre-trip inspection, where you walk around the truck and explain what you are checking and why. You point out lights, tires, mirrors, coupling devices, and safety equipment. The examiner is not looking for you to touch everything — you demonstrate your knowledge by describing what a safe truck looks like.

The second part is basic control. You perform maneuvers in a closed course or parking lot: backing in a straight line, backing into an offset alley, and performing a 90-degree alley dock. These test your ability to control the vehicle's length and width. You are judged on smoothness, accuracy, and whether you stay within marked boundaries.

The third part is on-road driving. You drive the truck on public roads for 30 to 45 minutes while the examiner observes. You will encounter turns, intersections, highway driving, and various traffic conditions. The examiner watches how you use mirrors, signal, brake, accelerate, and respond to other vehicles. You must follow all traffic laws and demonstrate safe judgment throughout.

Medical Certificate Requirements Before Testing

Before you can take either the written or driving test, you must obtain a Medical Certificate from a certified medical examiner. This is not a regular doctor's visit — the examiner must be listed on the National Registry of Certified Medical Examiners maintained by the Federal Motor Carrier Safety Administration (FMCSA). Your regular physician may not be on this list, so you will likely need to find a different provider.

The medical exam checks your vision, hearing, blood pressure, and general health. The examiner is looking for conditions that could make you unsafe to operate a large truck. If you have certain medical conditions — uncontrolled diabetes, heart disease, or severe sleep apnea, for example — you may be denied certification or given a certificate with restrictions. The Medical Certificate is valid for two years from the date of the exam.

You must carry your Medical Certificate with you when you take the CDL tests and when you drive commercially. If your certificate expires, you cannot legally operate a commercial vehicle, even if your CDL license itself is still valid.

Training Options and Their Role in Test Preparation

CDL training is not legally required to take the test, but most people find it necessary. Training programs range from four weeks to several months and teach vehicle operation, safety procedures, and test-taking strategies. Some programs are offered by community colleges, vocational schools, or private truck driving schools. Others are offered by trucking companies as part of hiring.

A formal training program typically includes classroom instruction on regulations and safety, hands-on practice with a truck and trailer, and supervised driving. Instructors teach you how to perform the pre-trip inspection, how to back the truck, and how to handle the vehicle on the road. They also familiarize you with the written test content and help you practice the specific maneuvers you will face on the driving test.

The cost of training varies widely. Private schools may charge $3,000 to $8,000 for a program. Community college programs may cost less but take longer. Some trucking companies offer free or subsidized training in exchange for a commitment to work for them after you obtain your CDL. If you are considering company-sponsored training, read the contract carefully — some require you to repay training costs if you leave within a certain period.

Retesting Rules and What Happens if You Fail

If you fail the written test, you can retake it. Most states allow you to retake it within a few days or weeks, though some require a waiting period. There is usually no limit on how many times you can retake the written exam, but check your state's rules.

The driving test is more restrictive. If you fail, you must wait before retesting — typically 14 days in many states, though this varies. Some states limit how many times you can retake the driving test within a certain period. A few states require you to retake the written test if you fail the driving test more than once. Understand your state's specific rules before you schedule your first driving test appointment.

Reasons for failing the driving test include hitting cones during maneuvers, failing to signal, unsafe lane changes, improper mirror checks, or any traffic violation during the on-road portion. The examiner will tell you which areas caused the failure so you can focus your practice before the next attempt.

State Variations in Testing and Scheduling

CDL testing rules and procedures vary by state. Some states allow you to take the written test at any DMV office; others have specific testing centers. Some states offer the driving test on weekdays only; others offer weekend appointments. Wait times for the driving test range from a few weeks to several months depending on your state and how busy the testing centers are.

Your state may also have different rules about which endorsements you can add at the same time, whether you must pass the written test before scheduling the driving test, and what documents you need to bring. Contact your state's DMV before you begin training to understand the exact sequence and requirements where you live.

Some states also allow third-party examiners — private testing facilities certified by the state — to administer the driving test. This may reduce wait times in your area. Ask your DMV whether third-party testing is available and whether it costs more than the state-administered test.

Frequently Asked Questions

Do I need formal training to pass the CDL test?

No, formal training is not legally required. However, most people find it very difficult to pass the driving test without hands-on practice with a truck and trailer. Self-study for the written test is possible, but learning to back a truck or perform a pre-trip inspection without instruction is challenging. Many people who attempt the test without training fail the driving portion on their first attempt.

How long does it take to get a CDL from start to finish?

This depends on your training choice and your state's testing schedule. A four-week training program plus waiting time for the driving test appointment could take two to three months total. A longer program or a state with long wait times could take six months or more. If you fail either test and need to retake it, add additional weeks.

Can I take the written test without a Medical Certificate?

No. You must have a valid Medical Certificate before you take either the written or driving test. Schedule your medical exam first, obtain the certificate, and then schedule your written test. The Medical Certificate is valid for two years, so you have time to take both tests after you obtain it.

What happens if I fail the driving test?

You will be told which areas caused the failure. You can retake the test after a waiting period — typically 14 days, though this varies by state. You can practice with a trainer or on your own before the next attempt. Some states require you to retake the written test if you fail the driving test multiple times within a certain period.

Do I need to bring my own truck to the driving test?

No. Your state provides a truck for the test, or you arrange one through your training program. The truck must meet certain safety and equipment standards set by your state. You cannot use your personal vehicle for the CDL driving test.