CDL Exam Prep

CDL Practice Tests

Prepare for your Commercial Driver's License exam with 130+ practice questions across 6 categories. Each question includes detailed explanations to help you understand the material — not just memorize answers.

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Study aid only. StudyItAll is not affiliated with any DMV or state agency, and this is not official test material. Question content follows the federally standardized FMCSA knowledge topics — always confirm details in your state's official CDL manual.

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CDL Pro · $19 once

50 random questions · 60-minute timer · 80% to pass — the closest thing to test day.

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Audio Study Guides

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Listen to all six topics hands-free — study between loads or on a break. No app, no download.

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Visual Study Guides

Reference diagrams to help you study key CDL concepts.

Truck Inspection Points

1

Engine Compartment

Oil level, coolant, belts, hoses, leaks

2

Cab / Controls

Gauges, mirrors, steering play, wipers, horn

3

Headlights & Signals

All lights working, clean, proper color

4

Tires & Wheels

Tread depth (4/32 front, 2/32 others), inflation, lug nuts

5

Brakes

Drums, pads, hoses, slack adjusters, air lines

6

Exhaust System

Securely mounted, no leaks, not near wiring

7

Coupling / 5th Wheel

Kingpin locked, platform secure, air/electric lines

8

Cargo / Trailer

Load secured, doors latched, placards if hazmat

9

Rear of Vehicle

Tail lights, reflectors, mud flaps, ICC bumper

Air Brake System Flow

Air CompressorGenerates compressed air
GovernorControls cut-in/cut-out
Air TanksStore compressed air
Brake PedalDriver input valve
Brake ChambersApply braking force
Key pressures: Governor cut-in ~100 psi | Cut-out ~125 psi | Low-pressure warning at 60 psi | Spring brakes engage at 20-45 psi

HazMat Placard Classes

1
Explosives
2
Gases
3
Flammable Liquids
4
Flammable Solids
5
Oxidizers
6
Toxic/Poison
7
Radioactive
8
Corrosive
9
Miscellaneous

Road Sign Shapes

STOPStop
YIELDYield
WARNINGWarning
SPEEDRegulatory
SCHOOLSchool
RRRailroad

CDL Exam Tips

Passing Score

You need 80% or higher to pass each section of the CDL knowledge test.

Study Strategy

Focus on one category at a time. Review explanations for every wrong answer.

Air Brakes Endorsement

If you don't pass the Air Brakes test, you'll receive a restriction on your CDL.

HazMat Endorsement

The HazMat endorsement requires a separate TSA background check and fingerprinting.

Pre-Trip Inspection

Many states require a hands-on vehicle inspection as part of the CDL skills test.

Test Day

Bring two forms of ID, your medical certificate, and any required fees. Arrive early.