Oregon General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Oregon CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 of 25 · Cargo
Which is correct about cargo and weight balance?
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A.
Heavy cargo should always be at the rear
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B.
Cargo should be balanced and secured to prevent shifting
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C.
Side-to-side balance does not matter
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D.
Top-heavy loads improve stability
Correct answer: B.
Cargo must be evenly balanced and well secured. Top-heavy loads increase rollover risk.
Question 2 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 3 of 25 · CDL Rules
Refusing a chemical test for alcohol or drugs while operating a CMV will result in:
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A.
A warning
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B.
A 90-day suspension
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C.
CDL disqualification of at least one year
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D.
A simple fine
Correct answer: C.
Refusal is treated the same as testing positive — minimum one-year disqualification.
Question 4 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 5 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
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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 6 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 7 of 25 · Inspection
Pre-trip inspection of the vehicle should be done in the same order each time so that you:
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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 8 of 25 · Basic Control
Where should the wheel chocks be placed?
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A.
Behind one tire
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B.
In front of and behind tires on the same axle
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C.
Only when on a hill
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D.
Both front and rear tires of the steer axle
Correct answer: B.
Place chocks both in front of and behind the wheels to prevent the vehicle from rolling either way.
Question 9 of 25 · Communication
Communicating your intentions means:
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A.
Honking before each turn
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B.
Using turn signals, brake lights, and the horn appropriately
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C.
Flashing high beams at all drivers
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D.
Hand signals only at intersections
Correct answer: B.
Use signals, brake lights, and the horn properly to communicate. Hand signals supplement them.
Question 10 of 25 · Adverse Conditions
Black ice is:
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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 11 of 25 · Emergency Equipment
What three kinds of emergency equipment must you have in your vehicle?
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A.
Spare tire, fuses, and reflective triangles
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B.
Fire extinguisher, spare fuses (if equipped), and warning devices
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C.
First aid kit, water, and flares
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D.
Tool kit, fuel can, and flag
Correct answer: B.
You must have a fire extinguisher, spare electrical fuses (if equipped), and warning devices for stopped vehicles.
Question 12 of 25 · Speed Management
When you double your speed, your stopping distance is multiplied by approximately:
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A.
Two
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B.
Three
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C.
Four
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D.
Six
Correct answer: C.
Stopping distance grows with the square of speed. Doubling speed roughly quadruples the distance needed to stop.
Question 13 of 25 · Communication
When should you check your mirrors?
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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 14 of 25 · Inspection
Excessive heat in tires can:
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A.
Improve handling
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B.
Cause tire failure
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C.
Help fuel economy
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D.
Increase tire life
Correct answer: B.
Excessive heat causes blowouts and serious damage. Check for hot tires after driving.
Question 15 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 16 of 25 · Night Driving
Which of these is true about driving at night?
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A.
You can see further than during the day
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B.
Your reaction time is faster at night
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C.
You should reduce your speed
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D.
High beams should always be used
Correct answer: C.
You see less and farther obstacles appear later at night. Slow down so you can stop within the area lit by your headlights.
Question 17 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 18 of 25 · Following Distance
Following distance for a heavy vehicle traveling below 40 mph should be at least:
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A.
1 second per 10 feet of vehicle length
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B.
Half the length of the vehicle
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C.
Two seconds total
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D.
No specific amount required
Correct answer: A.
Use one second of following distance for every 10 feet of vehicle length below 40 mph; add a second above 40 mph.
Question 19 of 25 · Emergency Equipment
Which of these is the best way to prevent fires?
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A.
Smoking only outside the cab
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B.
Pre-trip inspection that includes electrical, fuel, and exhaust systems
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C.
Carrying a large fire extinguisher
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D.
Driving slowly
Correct answer: B.
A thorough pre-trip inspection that catches electrical, fuel, and exhaust defects is the best fire prevention.
Question 20 of 25 · Basic Control
You should use the parking brake:
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A.
Only when parking on hills
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B.
Whenever you leave the vehicle
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C.
Only when leaving the engine running
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D.
Only on slick surfaces
Correct answer: B.
Always set the parking brake whenever you leave your vehicle, regardless of the surface or grade.
Question 21 of 25 · CDL Rules
What is the legal blood alcohol concentration (BAC) limit for CDL drivers?
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A.
0.08%
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B.
0.05%
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C.
0.04%
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D.
0.02%
Correct answer: C.
Federal CDL law sets the BAC limit at 0.04%, half the limit for non-commercial drivers.
Question 22 of 25 · Driver Wellness
Which of the following is NOT a sign of fatigued driving?
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A.
Frequent yawning
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B.
Drifting from your lane
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C.
Rapid blinking and clear focus
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D.
Missing exits or traffic signs
Correct answer: C.
Rapid blinking with clear focus is not a fatigue sign. Yawning, drifting, and missing exits all are.
Question 23 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 24 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 25 of 25 · Inspection
When inspecting your vehicle, the engine should be:
-
A.
Running with the hood open
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B.
Off, with the parking brake set, before starting checks under the hood
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C.
Idling in gear
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D.
Warm but turned off only on hills
Correct answer: B.
Set the parking brake, turn off the engine, and chock the wheels before checking under the hood.
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 Oregon Driver and Motor Vehicle Services administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Oregon CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Inspection: 5 questions
- Basic Control: 3 questions
- Emergency Maneuvers: 2 questions
- CDL Rules: 2 questions
- Driver Wellness: 2 questions
- Communication: 2 questions
- Emergency Equipment: 2 questions
- Speed Management: 2 questions
- Cargo: 1 question
- Adverse Conditions: 1 question
- ABS: 1 question
- Night Driving: 1 question
- Following Distance: 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 Oregon 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 Oregon