CDL General Knowledge

First published: September 1, 2026Last verified: September 1, 2026Reviewed by the CertQuestUSA team

TL;DR

CDL General Knowledge: a 124-question practice bank for the real CDL Permit & Endorsement Exams standard, 2 full papers of 50 questions each with no repeats, every question citing the real regulation it comes from.

Where these questions come from

Every question in this bank cites a real source -- primarily FMCSA CDL Manual (77%) and 49 CFR (23%) of this exam's citations.

Not sure where you stand? Take the free diagnostic — 10 real questions across the exam's domains, no sign-up required, with a domain-by-domain breakdown at the end.

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2

full papers, no repeats

50

questions per paper

124

questions in the bank

What this exam covers

Accident Procedures & Fires6%
Alcohol & Other Drugs8%
Basic Control & Shifting10%
Emergency Maneuvers & Skid Control10%
Staying Alert, Fatigue & Hours of Service6%
Hazard Perception & Distracted/Aggressive Driving8%
Hazardous Materials Awareness (General Knowledge)2%
Mountain Driving4%
Night Driving & Extreme Conditions10%
Railroad-Highway Crossings4%
Seeing & Communicating8%
Speed & Space Management10%
Vehicle Inspection14%

5 real sample questions

What is the most important reason for performing a pre-trip inspection before every trip?

A. To satisfy your dispatcher that the truck left on time

B. To find problems that could cause a crash or breakdown before they happen on the road

C. To reduce the number of miles logged for the day

D. To avoid having to fill out any paperwork later

Source: FMCSA CDL Manual §2.1.1

A roadside inspector determines that a commercial motor vehicle has a safety defect serious enough to be an immediate hazard. What is the inspector authorized to do under 49 CFR 396.9?

A. Issue a warning only, since only the motor carrier can pull a vehicle from service

B. Declare the vehicle "out of service" until the defect is corrected

C. Impound the vehicle permanently

D. Fine the driver but allow the vehicle to continue to the next scheduled stop

Source: 49 CFR 396.9

Under the federal tire tread depth standard, what is the minimum tread depth allowed in any major tread groove on a steering axle tire?

A. 1/32 inch

B. 2/32 inch

C. 4/32 inch

D. 6/32 inch

Source: 49 CFR 393.75

What is the minimum tread depth required on non-steering axle tires of a commercial motor vehicle?

A. 1/32 inch

B. 2/32 inch

C. 3/32 inch

D. 4/32 inch

Source: 49 CFR 393.75

Under 49 CFR 392.7, a driver may not operate a commercial motor vehicle unless satisfied that certain systems are in good working order. Which of the following is included in that pre-trip requirement?

A. The radio and cab air-conditioning system

B. Service brakes, trailer brake connections, parking brake, tires, lights, and mirrors

C. The cruise control set speed

D. The fuel economy displayed on the dashboard computer

Source: 49 CFR 392.7

Real-world data for this exam

Heavy and Tractor-Trailer Truck Drivers: real median wageMay 2025$58,640/yr Unsafe Drivingsince 2023-01-01609,590 violations Part of the real CDL Driver career pathExplore ›

Frequently asked questions

How many questions are on the CertQuestUSA CDL General Knowledge practice test?

124 questions total, split into 2 full papers of 50 each with no repeats across papers.

What topics does the CDL General Knowledge test cover?

13 domains, with the heaviest weight on Vehicle Inspection (14%), Basic Control & Shifting (10%), and Emergency Maneuvers & Skid Control (10%).

Where do CertQuestUSA's CDL General Knowledge questions come from?

Primarily FMCSA CDL Manual (77%) and 49 CFR (23%) of this bank's citations -- computed directly from this exam's own question sources, not a generic description.

Is there a free diagnostic for CDL General Knowledge?

Yes -- 10 real questions across the exam's domains, no sign-up required, with a domain-by-domain breakdown at the end.

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