Commercial Driver’s License (CDL) Class A
Practice Exam Questions With Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
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1. What is the primary purpose of a pre-trip inspection?
A. To clean the vehicle
B. To ensure the vehicle is safe to operate
C. To reduce fuel consumption
D. To improve driver comfort
Answer: B
Rationale: A pre-trip inspection is essential for identifying safety
issues before driving, ensuring the vehicle is roadworthy and
compliant with regulations.
2. What is the minimum tread depth for front tires on a commercial
vehicle?
A. 1/32 inch
B. 2/32 inch
, C. 4/32 inch
D. 6/32 inch
Answer: C
Rationale: Front tires must have at least 4/32 inch tread depth to
maintain proper traction and steering control.
3. What does the air compressor governor control?
A. Fuel injection timing
B. Engine speed
C. Air pressure cut-in and cut-out
D. Brake pedal sensitivity
Answer: C
Rationale: The governor regulates when the compressor starts
and stops building air pressure.
4. When should you use wheel chocks?
A. While driving downhill
B. During fueling
C. When parked on an incline
D. Only in cold weather
Answer: C
, Rationale: Wheel chocks prevent unintended movement when
parked, especially on slopes.
5. What is the legal blood alcohol concentration (BAC) limit for CDL
drivers?
A. 0.08%
B. 0.06%
C. 0.04%
D. 0.02%
Answer: C
Rationale: CDL drivers are held to stricter standards, with a
0.04% BAC limit.
6. What is “gross vehicle weight rating” (GVWR)?
A. The weight of cargo only
B. Maximum safe operating weight of the vehicle
C. Weight of passengers
D. Weight of fuel
Answer: B
Rationale: GVWR includes vehicle, cargo, passengers, and fuel.
, 7. What is the purpose of the fifth wheel?
A. To steer the trailer
B. To support engine weight
C. To couple the tractor and trailer
D. To reduce braking distance
Answer: C
Rationale: The fifth wheel connects the tractor to the trailer
securely.
8. What should you do if air pressure drops below 60 psi?
A. Continue driving
B. Stop immediately
C. Increase speed
D. Turn off engine
Answer: B
Rationale: Low air pressure can lead to brake failure, requiring
immediate stopping.
9. What is the following distance rule for large trucks?
A. 1 second per 10 feet
B. 2 seconds total
Practice Exam Questions With Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. What is the primary purpose of a pre-trip inspection?
A. To clean the vehicle
B. To ensure the vehicle is safe to operate
C. To reduce fuel consumption
D. To improve driver comfort
Answer: B
Rationale: A pre-trip inspection is essential for identifying safety
issues before driving, ensuring the vehicle is roadworthy and
compliant with regulations.
2. What is the minimum tread depth for front tires on a commercial
vehicle?
A. 1/32 inch
B. 2/32 inch
, C. 4/32 inch
D. 6/32 inch
Answer: C
Rationale: Front tires must have at least 4/32 inch tread depth to
maintain proper traction and steering control.
3. What does the air compressor governor control?
A. Fuel injection timing
B. Engine speed
C. Air pressure cut-in and cut-out
D. Brake pedal sensitivity
Answer: C
Rationale: The governor regulates when the compressor starts
and stops building air pressure.
4. When should you use wheel chocks?
A. While driving downhill
B. During fueling
C. When parked on an incline
D. Only in cold weather
Answer: C
, Rationale: Wheel chocks prevent unintended movement when
parked, especially on slopes.
5. What is the legal blood alcohol concentration (BAC) limit for CDL
drivers?
A. 0.08%
B. 0.06%
C. 0.04%
D. 0.02%
Answer: C
Rationale: CDL drivers are held to stricter standards, with a
0.04% BAC limit.
6. What is “gross vehicle weight rating” (GVWR)?
A. The weight of cargo only
B. Maximum safe operating weight of the vehicle
C. Weight of passengers
D. Weight of fuel
Answer: B
Rationale: GVWR includes vehicle, cargo, passengers, and fuel.
, 7. What is the purpose of the fifth wheel?
A. To steer the trailer
B. To support engine weight
C. To couple the tractor and trailer
D. To reduce braking distance
Answer: C
Rationale: The fifth wheel connects the tractor to the trailer
securely.
8. What should you do if air pressure drops below 60 psi?
A. Continue driving
B. Stop immediately
C. Increase speed
D. Turn off engine
Answer: B
Rationale: Low air pressure can lead to brake failure, requiring
immediate stopping.
9. What is the following distance rule for large trucks?
A. 1 second per 10 feet
B. 2 seconds total
