Take a free Texas CDL practice test online: a full 50-question paper with every answer explained, no sign-up, scored by topic. The full 124-question bank and the timed simulator are $14.99 for 30 days.
CDL General Knowledge (Texas): 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 written to the regulation it comes from.
Where these questions come from
Every question in this bank cites a source -- primarily FMCSA CDL Manual (77%) and 49 CFR (23%) of this exam's citations.
Take a full practice test free. 50 real questions built to the exam's domain weights, every answer explained, no sign-up required, with a domain-by-domain score at the end.
Want the whole bank for CDL General Knowledge (Texas)? One payment of $14.99 gives you 30 days of full access to this exam. It does not renew. No account needed to buy, and there is a 7-day money-back guarantee.
The knowledge tested here is federal (FMCSA) and identical nationwide -- what varies by state is who administers it and under what terms. Researched directly from Texas Department of Public Safety (DPS)'s own site, verified 2026-09-03.
Texas discontinued Spanish-language CDL knowledge testing effective June 1, 2026 -- all CDL knowledge exams are now English-only, aligning with the federal FMCSA English Language Proficiency enforcement push. Interpreters are prohibited.
Section 14 commercial rules apply to certain intrastate operations.
Texas applicants: check the required tests before studying
Confirm your license class and applicable knowledge tests with Texas DPS. General knowledge does not replace Texas commercial rules or additional required sections.
Use the diagnostic to identify weak driving-safety topics, then compare them with the current Texas manual.
Prepare for the language used in the real test: Texas DPS says CDL knowledge exams are administered exclusively in English from June 1, 2026. Spanish practice, where available here, is a learning aid.
This page uses shared national CDL knowledge content. Texas application requirements are a separate step; this preview is not a complete Texas commercial-rules course.
Why should water generally not be used on an electrical (Class C) fire?
A. Water has no effect on any type of fire
B. Water can conduct electricity, creating a shock hazard for the person fighting the fire
C. Water is too heavy to transport in a fire extinguisher
D. There is no danger in using water on an electrical fire
Show answer and reasoning
Correct answer: B. Water can conduct electricity, creating a shock hazard for the person fighting the fire
A: Water does have a real effect on some fires, which is part of why using it on the wrong class is dangerous.
C: The weight of water is not the reason it is avoided on electrical fires; the shock hazard is.
D: There is a genuine electrocution risk, which is exactly why water is avoided on this fire class.
Source: FMCSA CDL Manual §2.21
If the service brakes fail while descending a grade, what is a recommended emergency action?
A. Shift into a higher gear to try to outrun the failure
B. Downshift, use the emergency/parking brake progressively, and look for an escape route such as a runaway ramp
C. Turn off the engine immediately while still moving at speed
D. Release the steering wheel to focus entirely on the pedals
Show answer and reasoning
Correct answer: B. Downshift, use the emergency/parking brake progressively, and look for an escape route such as a runaway ramp
A: Shifting to a higher gear reduces engine braking exactly when more control is needed.
C: Turning off the engine while moving can disable power steering and other systems, making the vehicle harder to control.
D: Releasing the steering wheel removes directional control precisely when it is most needed during a brake failure.
Source: FMCSA CDL Manual §2.17
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
Show answer and reasoning
Correct answer: C. 4/32 inch
A: 1/32 inch is below the federal minimum for any position.
B: 2/32 inch is the minimum for tires on axles other than the steering axle.
D: 6/32 inch is deeper than the regulation requires, though additional depth is never unsafe.
Source: 49 CFR 393.75
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
Show answer and reasoning
Correct answer: B. To find problems that could cause a crash or breakdown before they happen on the road
A: A pre-trip inspection has nothing to do with dispatch timing.
C: Inspection findings do not change logged mileage.
D: A pre-trip inspection actually creates required paperwork (the inspection report), not less of it.
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
Show answer and reasoning
Correct answer: B. Declare the vehicle "out of service" until the defect is corrected
A: 396.9 gives the inspector authority to declare the vehicle out of service, not merely to warn.
C: Out-of-service means repaired and released, not permanent impoundment.
D: An out-of-service order prohibits further operation until the defect is fixed, not a fine-and-continue arrangement.
Where can I take a free Texas CDL practice test online?
Right here. CertQuestUSA's free Texas CDL practice test online is a full 50-question practice paper built to the real exam's domain weights, with every answer explained, with no sign-up and no credit card, and shows your score by topic at the end. The full 124-question bank, with every answer explained and cited to the regulation it comes from, is $14.99 for a 30-day pass that never renews.
How many questions are on the CertQuestUSA CDL General Knowledge (Texas) 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 (Texas) 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 (Texas) 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 CDL General Knowledge (Texas) practice test?
Yes -- one full 50-question practice paper built to the exam's domain weights, free with no sign-up, with every answer explained and a domain-by-domain score at the end.
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