CDL (commercial driver’s license) EXAM LATEST
2026 UPDATE 100 QUESTIONS AND DETAILED
VERIFIED ANSWERS FROM ACTUAL EXAMS TEST
GRADE A+
1. What is the main purpose of a pre-trip inspection?
A. To save fuel
B. To check for mechanical problems
C. To clean the vehicle
D. To test driving skills
Answer: B
Rationale: A pre-trip inspection ensures the vehicle is safe to operate by identifying
defects before driving.
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 for safe steering
and traction.
3. When should you use your horn?
A. To greet other drivers
B. To express frustration
,C. To warn others of danger
D. At all intersections
Answer: C
Rationale: The horn is used strictly as a safety warning device.
4. What does a flashing red traffic light mean?
A. Proceed with caution
B. Stop completely
C. Speed up
D. Yield only
Answer: B
Rationale: A flashing red light requires a full stop before proceeding.
5. What is the proper following distance for a commercial vehicle?
A. 1 second per 10 feet
B. 1 second per 20 feet
C. 1 second per 30 feet
D. 1 second per 40 feet
Answer: A
Rationale: CDL guidelines recommend at least 1 second per 10 feet of vehicle
length.
6. What is “hydroplaning”?
A. Driving uphill
B. Tires losing contact with the road due to water
C. Engine overheating
D. Braking failure
,Answer: B
Rationale: Hydroplaning occurs when water prevents tire-road contact.
7. When driving in fog, you should use:
A. High beams
B. Parking lights
C. Low beams
D. Hazard lights only
Answer: C
Rationale: Low beams reduce glare and improve visibility in fog.
8. What is the safest way to handle a tire blowout?
A. Brake hard
B. Steer sharply
C. Hold steering wheel firmly and slow down
D. Accelerate
Answer: C
Rationale: Maintaining control and gradually slowing prevents rollover.
9. What is the maximum legal blood alcohol concentration (BAC) for CDL
drivers?
A. 0.08%
B. 0.04%
C. 0.02%
D. 0.10%
Answer: B
Rationale: CDL drivers are held to a stricter BAC limit of 0.04%.
, 10. What should you do before changing lanes?
A. Honk
B. Accelerate
C. Check mirrors and blind spots
D. Brake suddenly
Answer: C
Rationale: Checking mirrors and blind spots prevents collisions.
11. What is “off-tracking”?
A. Losing control on ice
B. Rear wheels taking a different path than front wheels
C. Engine failure
D. Braking delay
Answer: B
Rationale: Large vehicles’ rear wheels follow a shorter path during turns.
12. When should you use hazard warning lights?
A. While speeding
B. When parked illegally
C. When stopped on the roadside
D. At all intersections
Answer: C
Rationale: Hazard lights alert other drivers to a stopped or disabled vehicle.
13. What is the purpose of ABS (Anti-lock Braking System)?
2026 UPDATE 100 QUESTIONS AND DETAILED
VERIFIED ANSWERS FROM ACTUAL EXAMS TEST
GRADE A+
1. What is the main purpose of a pre-trip inspection?
A. To save fuel
B. To check for mechanical problems
C. To clean the vehicle
D. To test driving skills
Answer: B
Rationale: A pre-trip inspection ensures the vehicle is safe to operate by identifying
defects before driving.
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 for safe steering
and traction.
3. When should you use your horn?
A. To greet other drivers
B. To express frustration
,C. To warn others of danger
D. At all intersections
Answer: C
Rationale: The horn is used strictly as a safety warning device.
4. What does a flashing red traffic light mean?
A. Proceed with caution
B. Stop completely
C. Speed up
D. Yield only
Answer: B
Rationale: A flashing red light requires a full stop before proceeding.
5. What is the proper following distance for a commercial vehicle?
A. 1 second per 10 feet
B. 1 second per 20 feet
C. 1 second per 30 feet
D. 1 second per 40 feet
Answer: A
Rationale: CDL guidelines recommend at least 1 second per 10 feet of vehicle
length.
6. What is “hydroplaning”?
A. Driving uphill
B. Tires losing contact with the road due to water
C. Engine overheating
D. Braking failure
,Answer: B
Rationale: Hydroplaning occurs when water prevents tire-road contact.
7. When driving in fog, you should use:
A. High beams
B. Parking lights
C. Low beams
D. Hazard lights only
Answer: C
Rationale: Low beams reduce glare and improve visibility in fog.
8. What is the safest way to handle a tire blowout?
A. Brake hard
B. Steer sharply
C. Hold steering wheel firmly and slow down
D. Accelerate
Answer: C
Rationale: Maintaining control and gradually slowing prevents rollover.
9. What is the maximum legal blood alcohol concentration (BAC) for CDL
drivers?
A. 0.08%
B. 0.04%
C. 0.02%
D. 0.10%
Answer: B
Rationale: CDL drivers are held to a stricter BAC limit of 0.04%.
, 10. What should you do before changing lanes?
A. Honk
B. Accelerate
C. Check mirrors and blind spots
D. Brake suddenly
Answer: C
Rationale: Checking mirrors and blind spots prevents collisions.
11. What is “off-tracking”?
A. Losing control on ice
B. Rear wheels taking a different path than front wheels
C. Engine failure
D. Braking delay
Answer: B
Rationale: Large vehicles’ rear wheels follow a shorter path during turns.
12. When should you use hazard warning lights?
A. While speeding
B. When parked illegally
C. When stopped on the roadside
D. At all intersections
Answer: C
Rationale: Hazard lights alert other drivers to a stopped or disabled vehicle.
13. What is the purpose of ABS (Anti-lock Braking System)?
