What Are the 3 Tests You Must Pass for Your CDL Permit?

Every state follows baseline federal guidelines established by the Federal Motor Carrier Safety Administration (FMCSA). However, states may have small variations in procedures, documentation requirements, scheduling rules, or testing logistics. That is why reviewing your state’s CDL Manual is essential. While the structure of the CDL permit tests remains consistent nationwide, the exact administrative process can vary slightly depending on where you apply.

Understanding what are the 3 tests for CDL permit is the first real step toward building a safe and successful trucking career.

CDL permit vs. CDL license: where the 3 permit tests fit in the full CDL process

Many new drivers confuse the CDL permit phase with the full licensing process. The truth is that earning your CLP is only the beginning.

The CDL pathway follows three structured steps.

Step 1: Get the Commercial Learner’s Permit (CLP)

To obtain your CLP, you must pass the required written knowledge tests for the type of CDL you are pursuing. Your driving record is reviewed, your medical qualifications are verified, and you must provide proof of identity and residency according to state requirements. Once issued, the CLP allows you to practice driving a commercial vehicle under supervision.

At this stage, you are in the permit phase. This phase focuses entirely on written knowledge exams and supervised practice.

Step 2: Complete Entry-Level Driver Training (ELDT)

For first-time Class A or Class B applicants who were issued a CLP on or after February 7, 2022, Entry-Level Driver Training (ELDT) is federally required before you can take the CDL skills test. ELDT includes theory instruction and behind-the-wheel training completed through a registered training provider listed in the FMCSA Training Provider Registry.

While there is no federal requirement to complete theory training before applying for a CLP, ELDT must be completed before moving forward to the licensing exam.

Step 3: Get the Commercial Driver’s License (CDL)

After holding your CLP for at least 14 days and completing any required ELDT training, you become eligible for the CDL skills test. This is the license phase.

The CDL skills test consists of three components:

• Pre-trip vehicle inspection
• Basic vehicle controls test
• Road test

Before you take the CDL permit tests: what you must have ready

Preparation for the CDL permit tests starts long before you sit down at a DMV testing station. The process is structured, and missing even one requirement can delay your progress.

Get your state’s CDL Manual

Your first step should always be obtaining your state’s official CDL Manual. It is available at state field locations, downloadable from your state’s website, and often printable in full. While federal guidelines set the foundation, each state may include specific procedures, documentation rules, and testing details. The manual outlines exactly what will appear on the General Knowledge, Air Brakes, and Combination Vehicles tests. Studying anything else without reviewing this manual first is a mistake.

Decide your CDL goal

Before testing, you must decide what type of CDL you are pursuing.

• Class A – Required for tractor-trailers and combination vehicles exceeding 26,001 lbs with trailers over 10,000 lbs.
• Class B – Required for single vehicles over 26,001 lbs, such as dump trucks, buses, and box trucks.
• Class C – Applies to certain smaller commercial vehicles transporting passengers or hazardous materials.

You should also determine whether you need endorsements, such as school bus, tank vehicle, passenger, or hazardous materials. Each endorsement may require additional written testing and, in some cases, skills testing.

Eligibility checks and paperwork

Getting a Commercial Learner’s Permit involves more than passing knowledge exams. Your eligibility must be verified through several checks:

• A 10-year driving record review across all 50 states and the District of Columbia. This ensures no disqualifying violations exist.
• Medical qualification, which commonly includes obtaining a DOT medical card through a certified DOT physical.
• State-specific documentation, including proof of identity, Social Security number, and residency.
• Payment of applicable CLP fees, which vary by state.

Having these requirements organized in advance streamlines your testing experience and prevents unnecessary delays.

Test 1: General Knowledge Test (what it covers and what it’s really testing)

The General Knowledge Test forms the foundation of all CDL permit testing. It applies to every CDL applicant, regardless of vehicle class or endorsements.

What the General Knowledge test is designed to prove

This test confirms that you understand the baseline safety rules, operational principles, and legal responsibilities that apply to all commercial drivers. It measures whether you grasp the fundamentals of operating a commercial motor vehicle safely before moving into supervised training.

The purpose is not memorization. It is to ensure you can think like a professional driver.

High-impact topics to expect

Safe driving practices

You will be tested on how to manage space, maintain safe following distances, and adjust speed based on weather, traffic, and road conditions. Commercial vehicles require more stopping distance and wider turns than passenger cars. The test evaluates your understanding of mirror usage, blind spots, and emergency awareness.

Pre-trip vehicle inspections

Daily inspections are federally required. You must understand what to check before driving, including brakes, lights, tires, suspension, fluid levels, and coupling devices. The test emphasizes recognizing defects that could cause breakdowns or safety hazards. Detecting issues early prevents violations and accidents.

Vehicle control techniques

Commercial vehicles behave differently than standard cars. You must understand controlled braking, smooth acceleration, proper turning techniques, and basic shifting concepts. Stability awareness is critical, especially when operating heavy loads that can shift weight during turns.

Traffic laws and commercial vehicle regulations

The General Knowledge test covers truck-specific speed limits, weight restrictions, lane usage, signage compliance, and Hours of Service awareness. It also includes clearance awareness for bridges and overpasses. Violations can result in fines, points against your CDL, or disqualification.

Cargo handling and securement fundamentals

Improper cargo securement can cause load shifts that affect steering, braking, and vehicle balance. You must understand why proper weight distribution across axles matters and how unsecured cargo leads to rollover risks and roadside violations.

Hazard perception and accident prevention

This section tests your ability to identify potential road hazards early. You must understand scanning techniques, maintaining escape routes, and anticipating the actions of other drivers. Defensive driving is a core professional skill, and this test ensures you recognize risk before it escalates.

The General Knowledge test is comprehensive because it sets the baseline for everything else you will do as a commercial driver.

Test 2: Air Brakes Test (the test that prevents costly restrictions)

For most Class A applicants, the Air Brakes Test is mandatory. Many Class B vehicles also use air brake systems. This test directly affects what equipment you are legally allowed to operate.

Why the air brakes test is a big deal

Most heavy commercial vehicles rely on air brake systems. If you fail this test or do not take it when required, your license may carry an air brake restriction. That restriction can significantly limit your employment opportunities and prevent you from driving most tractor-trailers.

Passing the Air Brakes Test keeps your CDL flexible and marketable.

What you’ll be tested on

Air brake system components

You must understand the function of key components, including the air compressor, governor, reservoirs, brake chambers, slack adjusters, and valves. The test evaluates whether you know how these parts work together to build and maintain safe braking pressure.

Dual air brake systems

Many commercial vehicles use dual air systems to provide redundancy. If one system fails, the other may still allow partial braking. You must understand how these systems operate and how to monitor them during inspections.

Brake inspections and leak testing

You will be tested on how air pressure builds and holds within the system. This includes understanding timed leak-down procedures and recognizing unsafe pressure loss. Brake inspections are required daily, and failure to detect a leak can result in catastrophic brake failure.

Proper braking techniques

The test covers controlled braking, stab braking, and how to avoid brake fade during long downhill grades. Improper braking techniques can cause overheating, loss of control, or jackknifing. Understanding these methods is critical for safe vehicle operation.

The Air Brakes Test ensures you understand one of the most important safety systems in commercial transportation.

Test 3: Combination Vehicles Test (tractor-trailer knowledge that keeps rigs upright and connected)

If you are pursuing a Class A CDL, the Combination Vehicles Test is required. This test focuses on the unique dynamics of tractor-trailer operation.

What this test is focused on

Adding a trailer dramatically changes how a vehicle handles. The physics of braking, turning, and weight distribution become more complex. This test ensures you understand those changes before you begin supervised driving.

Improper handling of combination vehicles can result in jackknifing, rollovers, or trailer separation accidents. The knowledge tested here directly protects lives and equipment.

What you’ll be tested on

Coupling and uncoupling procedures

You must understand how the fifth wheel connection works, how to verify a secure coupling, and how to manage landing gear properly. Incorrect coupling can cause trailer separation while driving, which often results in severe accidents.

Driving characteristics of combination vehicles

Combination vehicles require wider turns, careful lane positioning, and awareness of trailer swing. Rearward amplification can cause the trailer to move more aggressively than the tractor during sudden maneuvers. The test ensures you understand these behaviors.

Trailer brake usage and inspections

You must understand the difference between service brakes and emergency brakes on the trailer. Inspection procedures ensure that both tractor and trailer braking systems function together properly.

Avoiding jackknifing and rollovers

Jackknifing occurs when the trailer folds toward the tractor due to traction loss or improper braking. Rollovers often result from excessive speed during turns or load shifts. The test evaluates your knowledge of how braking, traction, and turning interact.

Inspection requirements for coupled units

Combination vehicles require inspection of both tractor and trailer, as well as the coupling connection between them. Problems in any of these areas can affect stability, braking, and control.