Tennessee General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Tennessee CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 of 25 · Adverse Conditions
What should you do before driving in fog?
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A.
Use high beams to see further
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B.
Slow down and use low beams and fog lights if equipped
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C.
Speed up to clear the fog area
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D.
Follow another vehicle closely
Correct answer: B.
Slow down before entering fog. Use low beams and any installed fog lights.
Question 2 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 3 of 25 · Speed Management
When approaching a curve, you should:
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A.
Brake while in the curve
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B.
Slow down before entering the curve
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C.
Maintain highway speed
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D.
Use the engine brake throughout
Correct answer: B.
Reduce speed before entering the curve, then accelerate slightly through the curve for stability.
Question 4 of 25 · Driver Wellness
You should not eat or drink while driving because:
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A.
It is illegal in all states
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B.
Spills can distract you
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C.
You should not put both hands on the wheel
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D.
It might damage the vehicle
Correct answer: B.
Eating and drinking divert attention and create spill hazards.
Question 5 of 25 · Speed Management
You are driving a vehicle that could safely be driven at 55 mph on an open highway. The traffic is heavy and moving at 35 mph. The safest speed for your vehicle in this traffic is most likely:
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A.
25 mph
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B.
35 mph
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C.
45 mph
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D.
55 mph
Correct answer: B.
You should generally adjust to the speed of surrounding traffic when it is safe to do so.
Question 6 of 25 · Adverse Conditions
When a vehicle hydroplanes, the brakes:
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A.
Will work better than usual
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B.
May cause the vehicle to spin
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C.
Should be applied hard
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D.
Cause the engine to stall
Correct answer: B.
Braking on a hydroplaning surface can lock wheels and cause spins. Ease off the throttle instead.
Question 7 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 8 of 25 · Inspection
The proper way to test the service brake on a vehicle is to:
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A.
Pump the pedal three times
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B.
Push the brake pedal firmly while moving about 5 mph
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C.
Put the parking brake on
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D.
Listen for air leaks
Correct answer: B.
Move the vehicle forward at about 5 mph and apply the brake firmly. The vehicle should not pull to either side.
Question 9 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 10 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 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 · Communication
Drivers should signal their intentions at least:
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A.
Right at the moment of turning
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B.
50 feet before the turn
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C.
100 feet before the turn
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D.
In the city, no signaling needed
Correct answer: C.
Signal at least 100 feet before turning to give following drivers time to react.
Question 13 of 25 · Adverse Conditions
Hydroplaning is most likely to occur when:
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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 · Driver Wellness
Distracted driving includes:
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A.
Talking on a hand-held cell phone
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B.
Eating
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C.
Reading maps
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D.
All of the above
Correct answer: D.
All of these activities take attention from driving and are forms of distracted driving.
Question 15 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 16 of 25 · Driver Wellness
Aggressive drivers should be:
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A.
Confronted
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B.
Reported and given plenty of room
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C.
Followed closely
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D.
Passed quickly without signaling
Correct answer: B.
Stay clear of aggressive drivers and report dangerous behavior to authorities.
Question 17 of 25 · Backing
Which of these statements about backing a heavy vehicle is true?
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A.
Back in a curved path whenever possible
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B.
Avoid backing whenever you can
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C.
Back as quickly as possible
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D.
Use only the right mirror
Correct answer: B.
Avoid backing whenever you can. Park where you will be able to pull forward to leave.
Question 18 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 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 · 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 21 of 25 · Hazard Awareness
When approaching a vehicle with a flashing amber light, you should:
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A.
Speed up to pass it
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B.
Slow down and pass with caution
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C.
Stop and wait until the light is off
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D.
Honk and continue
Correct answer: B.
Amber flashing lights indicate a hazard or slow-moving vehicle. Slow down and pass carefully.
Question 22 of 25 · Night Driving
You should use low beam headlights:
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A.
Whenever you can
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B.
Within 500 feet of an oncoming vehicle and 500 feet behind another vehicle
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C.
Only in fog
-
D.
On lighted city streets only
Correct answer: B.
Use low beams within 500 feet of oncoming traffic and when following within 500 feet of another vehicle.
Question 23 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 24 of 25 · Hazard Awareness
Hazardous conditions exist when there are:
-
A.
Pedestrians and bicyclists
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B.
Children and elderly drivers
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C.
Distractions and bad weather
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D.
All of the above
Correct answer: D.
Hazards include other road users, weather, distractions, and changing road surfaces.
Question 25 of 25 · Inspection
What is the minimum tread depth for non-steering axle tires?
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A.
1/32 inch
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B.
2/32 inch
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C.
4/32 inch
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D.
6/32 inch
Correct answer: B.
Federal regulations require at least 2/32 inch on non-steering tires.
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 Tennessee Department of Safety — Driver Services administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Tennessee CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Adverse Conditions: 4 questions
- Driver Wellness: 4 questions
- Speed Management: 3 questions
- Inspection: 2 questions
- Night Driving: 2 questions
- Emergency Maneuvers: 2 questions
- Communication: 2 questions
- Hazard Awareness: 2 questions
- Mountain Driving: 1 question
- CDL Rules: 1 question
- Backing: 1 question
- Basic Control: 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 Tennessee 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 Tennessee