Oklahoma General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Oklahoma CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 of 25 · Backing
You should always try to park:
-
A.
So that you will have to back when leaving
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B.
So that you can pull forward when leaving
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C.
On the right shoulder of any highway
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D.
Without using the parking brake
Correct answer: B.
Park so that you can pull forward to leave. Backing should always be avoided when possible.
Question 2 of 25 · CDL Rules
Driving with a BAC of 0.04 or higher in a CMV will result in:
-
A.
A warning
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B.
A 30-day suspension
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C.
A CDL disqualification of at least one year
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D.
No penalty if off-duty
Correct answer: C.
A first offense disqualifies you for at least one year (three years if hauling hazardous materials).
Question 3 of 25 · Vehicle Dynamics
Empty trucks:
-
A.
Always stop more quickly than loaded trucks
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B.
Have less traction because there is less weight on the drive axles
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C.
Can take curves at higher speeds safely
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D.
Are not affected by wind
Correct answer: B.
Empty trucks have reduced traction on drive axles and require greater stopping distances than loaded trucks.
Question 4 of 25 · Cargo
How can you tell if your vehicle is overloaded?
-
A.
It rides higher than normal
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B.
It handles differently from when properly loaded
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C.
It uses less fuel
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D.
It accelerates faster
Correct answer: B.
Overloaded vehicles handle poorly — they accelerate slower, take longer to stop, and are harder to steer.
Question 5 of 25 · Adverse Conditions
When you have to drive into the sun and visibility is reduced, what should you do?
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A.
Use sunglasses and lower the visor
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B.
Use only your high beams
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C.
Maintain your normal speed
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D.
Speed up to get past the area
Correct answer: A.
Use sunglasses and the visor and slow down. Reduced visibility increases stopping distance.
Question 6 of 25 · Hazard Awareness
How can you tell if your truck or bus has a hazardous materials shipment?
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A.
It is moving slowly
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B.
Diamond-shaped placards are displayed
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C.
A flashing yellow light is on
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D.
It is following another truck
Correct answer: B.
Diamond-shaped placards on the vehicle indicate the presence of hazardous materials.
Question 7 of 25 · ABS
What does ABS do?
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A.
Helps you stop faster
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B.
Prevents wheels from locking up during hard braking
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C.
Replaces engine brakes
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D.
Eliminates the need for service brakes
Correct answer: B.
Antilock braking systems prevent wheel lockup, helping you maintain steering control during hard braking.
Question 8 of 25 · Communication
When should you check your mirrors?
-
A.
Only before changing lanes
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B.
Frequently, to know what is around your vehicle
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C.
When parking only
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D.
Only at intersections
Correct answer: B.
Check mirrors regularly to know what is happening around your vehicle.
Question 9 of 25 · Speed Management
Engine brakes (Jakes) should not be used:
-
A.
On dry pavement at highway speed
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B.
On slippery roads while loaded or empty
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C.
When descending a steep grade
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D.
Heading toward a long downhill
Correct answer: B.
Avoid engine brakes on slippery roads — they can cause the drive wheels to lose traction.
Question 10 of 25 · Speed Management
Whenever you double your speed, the impact in a crash is:
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A.
Doubled
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B.
The same
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C.
Four times greater
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D.
Half
Correct answer: C.
Crash energy increases with the square of speed — doubling speed quadruples crash forces.
Question 11 of 25 · Emergency Maneuvers
Stab braking is used:
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A.
Only on slippery roads
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B.
When you must stop quickly with non-ABS brakes
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C.
Whenever you stop
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D.
Only on downgrades
Correct answer: B.
Stab braking is an emergency technique used with non-ABS brakes: apply brakes fully, release when wheels lock, then reapply.
Question 12 of 25 · Inspection
What is the minimum tread depth for steering axle tires?
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A.
2/32 inch
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B.
4/32 inch
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C.
6/32 inch
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D.
8/32 inch
Correct answer: B.
Federal regulations require at least 4/32 inch tread depth on steering axle tires.
Question 13 of 25 · Adverse Conditions
Hydroplaning is most likely to occur when:
-
A.
Tires are properly inflated
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B.
Speed is below 30 mph
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C.
Roads are dry
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D.
Tires lose contact with the road on wet pavement
Correct answer: D.
Hydroplaning happens when water builds up between the tire and the road, causing loss of contact.
Question 14 of 25 · Speed Management
Engine retarders should be turned off when:
-
A.
Driving uphill
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B.
The road is wet, icy, or snow covered
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C.
Traffic is heavy
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D.
You are loaded
Correct answer: B.
Retarders can cause drive wheels to skid on slippery surfaces. Turn them off in poor traction conditions.
Question 15 of 25 · Inspection
Mirror adjustment should be checked:
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A.
Only at the start of the trip
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B.
Only when something seems wrong
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C.
Prior to the start of any trip and can only be checked accurately when the trailer(s) are straight
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D.
Once per week
Correct answer: C.
Adjust and check mirrors before each trip while the trailers are straight.
Question 16 of 25 · Inspection
Vehicle inspection is important because:
-
A.
Federal and state laws require it
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B.
Safety is at risk
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C.
Defects can save lives if found early
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D.
All of the above
Correct answer: D.
Inspections are legally required and prevent breakdowns and crashes by catching defects early.
Question 17 of 25 · Mountain Driving
What may happen if you don't shift gears properly when going up a hill?
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A.
You will use less fuel
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B.
The transmission will be damaged
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C.
You may lose control on a downgrade
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D.
Engine RPM will be too low
Correct answer: C.
Improper gear use can result in losing control of speed, especially on the way back down a hill.
Question 18 of 25 · Hours of Service
How often must a driver complete a written record of duty status?
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A.
Every 8 hours
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B.
Every 12 hours
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C.
Every 24 hours
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D.
Once a week
Correct answer: C.
A daily record of duty status (logbook) must be completed each 24-hour period.
Question 19 of 25 · Emergency Maneuvers
Which of the following is a sign of tire failure?
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A.
A loud "bang" sound
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B.
Vibration or thumping
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C.
Heavy steering or fishtailing
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D.
All of the above
Correct answer: D.
A bang, vibration, heavy steering, or fishtailing can all indicate tire failure.
Question 20 of 25 · Basic Control
Convex (curved) mirrors:
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A.
Make objects appear larger and closer than they really are
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B.
Make objects appear smaller and farther away than they really are
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C.
Provide a normal view
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D.
Are required only on doubles
Correct answer: B.
Convex mirrors widen the field of view but make objects look smaller and farther away.
Question 21 of 25 · Driver Wellness
What should you do when an aggressive driver confronts you?
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A.
Make eye contact and respond
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B.
Try to escape the situation safely and avoid eye contact
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C.
Slow down to teach a lesson
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D.
Speed up and pass
Correct answer: B.
Avoid engagement, give space, do not make eye contact, and report the behavior.
Question 22 of 25 · Emergency Maneuvers
What should you do if your brakes fail on a downgrade?
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A.
Pump the brakes vigorously
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B.
Look for an escape ramp or open area to slow down
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C.
Shift into neutral
-
D.
Turn off the engine
Correct answer: B.
If brakes fail, look for an escape ramp or a route that will slow your vehicle without endangering others.
Question 23 of 25 · Adverse Conditions
Black ice is:
-
A.
A thick layer of ice that is easily seen
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B.
A thin layer that looks wet pavement
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C.
Only found in the far north
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D.
Not a real road hazard
Correct answer: B.
Black ice is a thin, transparent layer that looks like wet pavement. It is extremely dangerous.
Question 24 of 25 · Inspection
Pre-trip inspection of the vehicle should be done in the same order each time so that you:
-
A.
Will look professional to other drivers
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B.
Will learn it well and not skip anything
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C.
Can finish faster
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D.
Pass the test more easily
Correct answer: B.
Following the same order helps prevent missed steps and builds reliable habits.
Question 25 of 25 · Cargo
Which is true about cargo securement?
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A.
Drivers are responsible for inspecting cargo
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B.
Cargo only needs to be inspected at the start of a trip
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C.
Securement is the shipper's sole responsibility
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D.
Once strapped, cargo never needs re-checking
Correct answer: A.
Drivers must inspect cargo and its securement at the start of the trip and re-check periodically.
About the General Knowledge Test
The General Knowledge test covers safe vehicle inspection, basic vehicle control, shifting gears, communicating, controlling speed, controlling distance, seeing hazards, distracted driving, aggressive drivers, communicating with other drivers, night driving, driving in fog, winter driving, hot weather driving, mountain driving, driving emergencies, anti-lock braking systems, skid recovery, accident procedures, fires, alcohol and other drugs, hazardous materials awareness, and staying alert and fit to drive. Every commercial driver in the United States must pass this test before any other CDL endorsement can be added.
The Oklahoma Department of Public Safety — Driver License Services administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Oklahoma CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Inspection: 4 questions
- Adverse Conditions: 3 questions
- Speed Management: 3 questions
- Emergency Maneuvers: 3 questions
- Cargo: 2 questions
- Backing: 1 question
- CDL Rules: 1 question
- Vehicle Dynamics: 1 question
- Hazard Awareness: 1 question
- ABS: 1 question
- Communication: 1 question
- Mountain Driving: 1 question
- Hours of Service: 1 question
- Basic Control: 1 question
- Driver Wellness: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for Oklahoma until you're ready for the official exam.
Tips specific to the General Knowledge test
The General Knowledge test is the foundation of every CDL. Topics include vehicle inspection, basic control, shifting, communicating, controlling speed, controlling space, hazard perception, distracted driving, night driving, fog, winter, hot weather, mountain driving, emergencies, anti-lock brakes, skid recovery, accident procedures, fires, alcohol, hazardous materials awareness, and staying alert. Most failures come from speeding through inspection-related questions; slow down and read carefully.
Other practice tests for Oklahoma