Michigan General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Michigan CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 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 2 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 3 of 25 · Night Driving
When meeting an oncoming vehicle at night, you should:
-
A.
Look directly at the headlights
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B.
Look toward the right side of the road
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C.
Switch to high beams
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D.
Increase speed
Correct answer: B.
Look toward the right side of the road to avoid being blinded by oncoming headlights.
Question 4 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 5 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 6 of 25 · Speed Management
Whenever you double your speed, the impact in a crash is:
-
A.
Doubled
-
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 7 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 8 of 25 · Basic Control
Convex (curved) mirrors:
-
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 9 of 25 · Mountain Driving
When driving down a long, steep downgrade, you should:
-
A.
Apply the brakes lightly to keep the speed down
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B.
Use a low gear and engine braking with intermittent braking
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C.
Coast in neutral
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D.
Press brakes continuously
Correct answer: B.
Use the appropriate low gear, rely on engine braking, and apply service brakes intermittently to control speed.
Question 10 of 25 · CDL Rules
Drivers convicted of driving a CMV without a valid CDL face:
-
A.
No fines for the first offense
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B.
Civil penalties up to $5,000 and possible jail time
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C.
Only a warning
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D.
A 30-day driving restriction
Correct answer: B.
Driving without a valid CDL can lead to significant federal civil penalties and possible criminal penalties.
Question 11 of 25 · CDL Rules
What document must you have to drive a CMV in interstate commerce?
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A.
A valid CDL with applicable endorsements
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B.
A current DOT physical (Medical Examiner's Certificate)
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C.
Both a valid CDL and a current Medical Examiner's Certificate
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D.
Only a regular driver license
Correct answer: C.
Interstate CMV drivers must have a valid CDL and a current medical examiner's certificate.
Question 12 of 25 · Speed Management
The total stopping distance of a CDL vehicle includes:
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A.
Perception, reaction, and braking distance
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B.
Only braking distance
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C.
Following distance and brake lag
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D.
Only the distance traveled while braking
Correct answer: A.
Total stopping distance is the sum of perception distance, reaction distance, brake lag, and braking distance.
Question 13 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
-
B.
35 mph
-
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 14 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 15 of 25 · Inspection
When checking the engine compartment, your vehicle should be:
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A.
Idling in neutral
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B.
On a slight incline
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C.
Parked on level ground with the parking brake set and wheels chocked
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D.
Running with the parking brake off
Correct answer: C.
Always inspect the engine compartment with the vehicle parked on level ground, parking brake set, and wheels chocked.
Question 16 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 17 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 18 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.
Question 19 of 25 · Speed Management
When you double your speed, your stopping distance is multiplied by approximately:
-
A.
Two
-
B.
Three
-
C.
Four
-
D.
Six
Correct answer: C.
Stopping distance grows with the square of speed. Doubling speed roughly quadruples the distance needed to stop.
Question 20 of 25 · Night Driving
You should use low beam headlights:
-
A.
Whenever you can
-
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 21 of 25 · Emergency Equipment
Most heavy vehicle fires are caused by:
-
A.
Hot tires from low pressure or under-inflated duals
-
B.
Cold weather
-
C.
Engine cooling system
-
D.
Exhaust pipes only
Correct answer: A.
Hot tires and brakes are leading causes. Inspect tires and brakes regularly to prevent fires.
Question 22 of 25 · Testing
When taking the road test, you will be expected to:
-
A.
Demonstrate the basic control skills only
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B.
Drive only on the highway
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C.
Show that you can perform safely in normal traffic
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D.
Drive only in residential areas
Correct answer: C.
The road test evaluates safe performance in actual traffic conditions.
Question 23 of 25 · Inspection
What is the most important reason for doing a vehicle inspection?
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A.
To meet DOT requirements
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B.
Safety for yourself and others
-
C.
To save fuel
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D.
To avoid roadside inspections
Correct answer: B.
Safety is the most important reason. A defective vehicle puts you, your cargo, and others at risk.
Question 24 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 25 of 25 · Emergency Equipment
Which of these is the best way to prevent fires?
-
A.
Smoking only outside the cab
-
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.
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 Michigan Secretary of State — Driver Services administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Michigan CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Speed Management: 5 questions
- Inspection: 4 questions
- CDL Rules: 3 questions
- Night Driving: 2 questions
- Basic Control: 2 questions
- Emergency Maneuvers: 2 questions
- Emergency Equipment: 2 questions
- Adverse Conditions: 1 question
- Mountain Driving: 1 question
- Hazard Awareness: 1 question
- Testing: 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 Michigan 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 Michigan