CDL Commercial Driver License Practice Test PDF (Free Printable 2026 September)
📚 Get ready for your CDL Commercial Driver License certification. Practice questions with step-by-step answer explanations and instant scoring.
The CDL (Commercial Driver License) knowledge tests are a series of FMCSA-mandated written exams you must pass before operating a commercial motor vehicle (CMV) on public roads. Depending on the class of vehicle you plan to drive and the cargo you'll carry, you may need to pass the General Knowledge test plus one or more endorsement tests. Every state administers CDL exams at its local DMV or licensing office.
If you are searching for a CDL practice test printable free, start with the free questions on this page: every answer comes with an explanation, and the study notes below cover the CDL exam topics in order.
Studying with a printable PDF lets you review CDL material away from a screen — ideal for truck stops, break rooms, or anywhere you have a few minutes to drill questions. Our free CDL practice test PDF covers General Knowledge, Air Brakes, Combination Vehicles, and Hazmat so you can prepare for all four of the most commonly required knowledge tests in one download.
What the CDL Knowledge Tests Cover
Each CDL knowledge test targets a specific area of commercial vehicle operation. Here is what you need to know for the four most common exams.
General Knowledge (Required for All CDL Classes)
The General Knowledge test is mandatory for every CDL applicant. It covers pre-trip vehicle inspection procedures (engine compartment, brake system, lights, tyres, mirrors, and emergency equipment), basic vehicle controls (steering, shifting manual and automatic transmissions, backing and turning), space management and following distances, night driving and adverse weather operation, mountain driving and runaway truck ramps, and cargo securement rules including weight distribution. You must also know FMCSA hours-of-service (HOS) regulations: the 11-hour driving limit, 14-hour on-duty window, 30-minute rest break requirement, and the 60/70-hour weekly limits.
Air Brakes Endorsement
Any driver operating a vehicle with air brakes must pass this test or have the air-brake restriction removed from their licence. Topics include the dual air brake system (primary and secondary circuits), the air compressor and governor (cut-in/cut-out pressure), air reservoirs, the brake pedal (foot valve), slack adjusters, the low-air-pressure warning (activates at 60 psi), spring parking brakes, brake fade and heat buildup on long downgrades, brake lag distance (approximately 32 feet at 55 mph), and the full pre-trip air brake check procedure (leak-down test, low-air warning test, parking brake test).
Combination Vehicles Endorsement
Required for Class A drivers, this test covers coupling and uncoupling procedures for semi-trailers and full trailers, the fifth-wheel locking mechanism inspection, dolly/pintle hook connections, anti-lock braking system (ABS) trailer relays, rearward amplification and crack-the-whip rollover risk, off-tracking in turns, and safe backing techniques. Understanding the difference between a B-train and A-train combination and knowing weight distribution rules for tandem axle placement are also tested.
Hazmat Endorsement
The Hazmat endorsement requires a TSA Security Threat Assessment (fingerprint-based background check) in addition to the written test. Test topics include DOT hazard classes and their placard requirements (explosive, flammable liquid, poison gas, radioactive, etc.), shipping papers (bill of lading, hazardous materials entry, emergency contact number), the Emergency Response Guidebook (ERG), loading and unloading rules (forbidden materials, quantity limits), the route restriction rules for tunnels and populated areas, and driver responsibility during a hazmat incident or spill.
CDL Class Distinctions
A Class A CDL covers any combination of vehicles with a GVWR over 26,001 lb where the towed unit exceeds 10,000 lb — primarily semi-trucks and tractor-trailers. A Class B CDL covers single vehicles over 26,001 lb (city buses, dump trucks, straight trucks) plus vehicles towing units under 10,000 lb. A Class C CDL covers vehicles that don't meet Class A or B thresholds but transport 16+ passengers or placardable hazmat quantities.
- ✓Complete the full pre-trip vehicle inspection sequence from memory (engine, brake, lights, tyres, mirrors)
- ✓Understand FMCSA hours-of-service rules: 11-hr drive, 14-hr duty window, 30-min break, 60/70-hr weekly limit
- ✓Know the dual air brake system components and the low-air-pressure warning threshold (60 psi)
- ✓Memorise brake lag distance and understand brake fade on long mountain downgrades
- ✓Perform the full air brake pre-trip check: leak-down test, low-air warning, parking brake hold test
- ✓Know coupling and uncoupling steps for semi-trailers including fifth-wheel inspection points
- ✓Understand rearward amplification, off-tracking, and rollover prevention for combination vehicles
- ✓Identify all DOT hazard classes, placard shapes/colours, and when placarding is required
- ✓Know the CDL class distinctions (A, B, C) and which endorsements each class requires
- ✓Understand FMCSA medical certificate requirements and which conditions are disqualifying
How to Use the Free CDL Practice Test PDF
Print the PDF and work through each section as a timed drill. For the General Knowledge section, aim for 50 questions in 60 minutes. For endorsement sections, hold yourself to 25–30 minutes. After scoring each section, flag every question you answered incorrectly and look up the relevant section in the FMCSA CDL handbook (available free at fmcsa.dot.gov).
Pair the printed PDF with our online CDL practice tests for immediate answer feedback and detailed explanations. The online tests also track your weak areas by topic so you can focus your remaining study time where it counts most. Many CDL candidates find that alternating between online and printed practice — using the PDF for final-day review — produces the best retention.
Pay special attention to the Air Brakes section even if you are not required to take that endorsement: understanding air brake systems helps with pre-trip inspection questions that appear on the General Knowledge test. Similarly, Hazmat placard questions occasionally appear as scenario-based questions in the General Knowledge test, so broad familiarity with all sections pays off.
- +Validates your knowledge and skills objectively
- +Increases job market competitiveness
- +Provides structured learning goals
- +Networking opportunities with other certified professionals
- −Study materials can be expensive
- −Exam anxiety can affect performance
- −Requires dedicated preparation time
- −Retake fees apply if you don't pass
🚛 What does the CDL General Knowledge test cover?
Vehicle inspection, basic vehicle control, shifting, backing, cargo securement, and FMCSA hours-of-service rules. It is required for every CDL class and has 50 questions, with 40 correct (80%) needed to pass.
START CDL PRACTICE TEST📄 Where can I find a printable CDL practice test?
Our free CDL practice test PDF is printable and covers General Knowledge, Air Brakes, Combination Vehicles, and Hazmat questions and answers, so you can study offline at truck stops or during breaks.
GET THE FREE PDF🔧 At what pressure does the low-air-pressure warning activate?
The low-air-pressure warning light and buzzer activate at 60 psi. Below that, you must stop driving safely and not continue until air pressure is restored, since braking power drops sharply.
PRACTICE AIR BRAKES QUESTIONS⏰ What are the FMCSA hours-of-service driving limits?
Drivers get an 11-hour driving limit inside a 14-hour on-duty window, a mandatory 30-minute break after 8 hours of driving, and weekly caps of 60 hours in 7 days or 70 hours in 8 days.
REVIEW HOS RULES🚚 What is coupling and why does it matter for Combination Vehicles?
Coupling connects a tractor to a trailer through the fifth-wheel locking mechanism. The test checks that you can inspect the kingpin, locking jaws, apron, and safety latch to confirm a secure connection before driving.
PRACTICE COMBINATION VEHICLES🧾 What extra step is required for the Hazmat endorsement?
You must pass a TSA Security Threat Assessment, a fingerprint-based background check costing about $86.50, in addition to the written Hazmat test covering placards, shipping papers, and the Emergency Response Guidebook.
PRACTICE HAZMAT QUESTIONS⚖️ What GVWR threshold defines a Class A CDL?
A Class A CDL covers combination vehicles with a total GVWR over 26,001 lb, where the towed unit itself exceeds 10,000 lb. This is the license class most tractor-trailer drivers need.
TAKE A CLASS A PRACTICE TEST🛣️ How far can a truck travel before the brakes fully engage?
Brake lag distance is roughly 32 feet at 55 mph for air-braked vehicles, the time between pressing the pedal and the brakes fully applying. Combined with reaction and stopping distance, this is why following distance matters so much.
REVIEW BRAKING FACTS🎯 What questions and answers does the CDL PDF include?
The free CDL questions and answers PDF gives you the exact question, four answer choices, and the correct answer explained in plain language, so you can self-check without needing internet access.
DOWNLOAD QUESTIONS AND ANSWERS🧠 Why do Hazmat placards show up on the General Knowledge test?
General Knowledge includes scenario-based questions that touch on hazmat placards and pre-trip inspection, since every CDL driver may encounter a placarded vehicle. Broad familiarity with all endorsement topics pays off, even ones you don't plan to take.
START FREE PRACTICE TESTOfficial Resources
- 49 CFR Part 383 — CDL Standards: the official federal regulation text defining CDL classes, knowledge test requirements, and endorsement rules, published by the U.S. government's electronic Code of Federal Regulations.
- 49 CFR Part 395 — Hours of Service: the full federal rule text for the 11-hour driving limit, 14-hour on-duty window, 30-minute break, and 60/70-hour weekly limits tested on the General Knowledge exam.
- TSA Hazmat Endorsement Program: the Transportation Security Administration's official page on the Security Threat Assessment required before any driver can obtain or renew a Hazmat endorsement.
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