CDL General Knowledge Practice Test 2026
Free CDL General Knowledge practice β the core written test every commercial driver must pass. Real test is in English; native-language explanations and English-term glossary help you learn. 50 questions on the real test (40/50 to pass). Endorsements like HazMat are a planned future addition. Practice every question free, then sit a 50-question mock scored to the real 80% pass line.
π CDL pre-trip inspection β step by step
A step-by-step pre-trip checklist β the 7-step method, engine, walkaround and the in-cab air brake check, with the auto-fail points β
π― Practice by Topic
Vehicle Inspection
Pre-trip, en-route and post-trip inspections: tires, brakes, steering, suspension, the seven-step method, and what to check and why.
Basic Control of Your Vehicle
Accelerating, steering, stopping, backing safely, and shifting gears: double-clutching, when to shift up/down, multi-speed axles, automatics, and retarders.
Seeing, Communicating & Managing Space
Looking far enough ahead, using mirrors and blind spots, signaling your intentions, communicating your presence, and managing the space all around a large commercial vehicle (CDL General Knowledge Β§2.4, Β§2.5, Β§2.7).
Controlling Speed
Adjusting speed to driving conditions: total stopping distance (perception + reaction + braking), how speed and weight affect stopping, traction and slippery surfaces, curves, visibility, traffic flow, downgrades and work zones.
Seeing Hazards & Distracted Driving
Spotting road and driver hazards early, reading clues to hidden hazards, always having a plan, distracted-driving dangers and the federal phone/texting bans for CMV drivers, and handling aggressive drivers and road rage.
Driving in Special Conditions
Night, fog, winter, very hot weather and mountain driving: headlights and glare, low beams and fog lights, slippery roads, wet brakes, brake fade, low gears and proper braking technique.
Railroad-Highway Crossings
Railroad-highway grade crossings: types of crossings, warning signs and devices, driving procedures, stopping safely, and crossing the tracks.
Driving Emergencies, ABS & Skid Control
Emergency steering and stopping, brake failure and escape ramps, tire blowouts, antilock braking systems (ABS), and recognizing and recovering from skids.
Accident Procedures & Fires
Accident scene: protect the area, flashers, reflective triangles, notify authorities, care for the injured. Fires: causes, prevention, and using a fire extinguisher (classes, base of the fire, upwind, don't open a burning trailer).
Transporting Cargo Safely
Cargo weight and balance: GVWR/GCWR/GAWR, legal weight limits, center of gravity and rollover, weight distribution over axles, blocking and bracing, tie-downs, header boards, covering loads, and cargo needing special attention.
π Study guides for this exam
π§° Jobs this credential opens
See jobs βπ§ Where this leads β the new immigrant career path
See how this exam fits a step-by-step ladder of U.S. licenses and certs β with median pay and the languages each real exam is offered in β
π What to Bring
- β
Proof of identity & U.S. residency
Documents required vary by state β check your state DMV's CDL page.
- β
Social Security number
- β
DOT medical certificate (for the CDL/CLP)
Most CDL applicants must be medically certified; bring your med card.
π How to Schedule
- 1
Study the CDL manual
Use your state's CDL manual (AAMVA model) for General Knowledge, Air Brakes and Combination Vehicles.
- 2
Apply for a Commercial Learner's Permit (CLP)
Pass the required knowledge tests at your state DMV to get the CLP, then practice before the skills test.
- 3
Check your state's specifics
Test languages, fees, scheduling (appointment vs walk-in) and retake rules vary by state β see the per-state table on this page.
π‘ Test Day Tips
- β’General Knowledge is required for every CDL. Focus on vehicle inspection, controlling/managing space, seeing hazards, and stopping distance.
- β’Learn the key English terms (pre-trip inspection, GCWR, following distance) even if you study in Chinese/Spanish β the real test is in English.
π Study Handbook
All practice questions are based on the sections below. Click any to read the official source.
π Official Resources
FMCSA β Commercial Driver's License β
Federal CDL overview, classes, endorsements, and English-language-proficiency rules.
AAMVA β CDL Testing β
The model CDL manual & testing system that state CDL manuals are based on.
Find your state's CDL manual & test info β
Languages, fees, scheduling and pass rules vary by state β see your state DMV (and our per-state table).
What the community says
Community-reported Β· unofficialWhat the community says about the CDL knowledge tests β Community report, unofficial; a sourced summary, not a first-person review. On difficulty, drivers say the General Knowledge test is manageable but Air Brakes and Combination Vehicles are the hardest sections β detail-heavy and a common reason for retakes; it rewards rote memorization of signs, inspection steps, and brake procedures. On process, you pass the written tests first to get a Commercial Learner's Permit (CLP), then train and take the skills test, with federal Entry-Level Driver Training (ELDT) required since 2022; endorsements (air brakes, combination, tanker, HazMat, passenger) are tested by target vehicle/cargo and vary a bit by state. On preparation, veterans advise drilling the hard sections and the official question pool repeatedly; note HazMat and some federal endorsements are English-only, so non-native speakers benefit from native-language study aids alongside each state's official test-language options.
β Frequently asked questions
How many questions are on the CDL General Knowledge test, and how many do I need to pass?
The CDL General Knowledge knowledge test has 50 questions. You must answer 40 correctly (80%) to pass.
How many questions can you miss on the CDL General Knowledge test?
You can miss up to 10 of the 50 questions and still pass.
What should I bring to the CDL General Knowledge test?
Proof of identity & U.S. residency β Documents required vary by state β check your state DMV's CDL page. Social Security number DOT medical certificate (for the CDL/CLP) β Most CDL applicants must be medically certified; bring your med card.
How do I schedule and take the CDL General Knowledge test?
1. Study the CDL manual: Use your state's CDL manual (AAMVA model) for General Knowledge, Air Brakes and Combination Vehicles. 2. Apply for a Commercial Learner's Permit (CLP): Pass the required knowledge tests at your state DMV to get the CLP, then practice before the skills test. 3. Check your state's specifics: Test languages, fees, scheduling (appointment vs walk-in) and retake rules vary by state β see the per-state table on this page.