New Jersey General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for New Jersey CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 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 2 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
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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 3 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 4 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 5 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 6 of 25 · Backing
You should always try to park:
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A.
So that you will have to back when leaving
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B.
So that you can pull forward when leaving
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C.
On the right shoulder of any highway
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D.
Without using the parking brake
Correct answer: B.
Park so that you can pull forward to leave. Backing should always be avoided when possible.
Question 7 of 25 · Hours of Service
How often must a driver complete a written record of duty status?
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A.
Every 8 hours
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B.
Every 12 hours
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C.
Every 24 hours
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D.
Once a week
Correct answer: C.
A daily record of duty status (logbook) must be completed each 24-hour period.
Question 8 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 9 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 10 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 11 of 25 · Mountain Driving
What are two special conditions where you should downshift?
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A.
Before starting down a hill and before entering a curve
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B.
In the city and at intersections
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C.
On bridges and tunnels
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D.
Whenever traffic slows
Correct answer: A.
Downshift before going down a hill and before entering a curve to maintain control.
Question 12 of 25 · Backing
The most important hand signal you and a helper should agree on is:
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A.
Speed up
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B.
Stop
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C.
Turn left
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D.
Back straight
Correct answer: B.
Always agree on a clear stop signal before backing. The helper must be able to stop you instantly.
Question 13 of 25 · CDL Rules
Drivers convicted of driving a CMV without a valid CDL face:
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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 14 of 25 · Inspection
When should you stop and check your tires after starting a long trip?
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A.
After 250 miles
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B.
Within the first 50 miles, then every 150 miles or 3 hours
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C.
Only when you stop for fuel
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D.
Tires don't need to be checked once you're moving
Correct answer: B.
Stop after the first 50 miles to check tires, then re-check every 150 miles or three hours.
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 · Rail Crossings
When approaching a railroad crossing without flashing lights or gates, you should:
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A.
Slow down, look, and listen for trains
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B.
Always come to a complete stop
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C.
Speed up to clear the crossing quickly
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D.
Sound horn but maintain speed
Correct answer: A.
Without active warning devices, slow down and look and listen carefully for an approaching train.
Question 17 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 18 of 25 · Speed Management
Engine brakes (Jakes) should not be used:
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A.
On dry pavement at highway speed
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B.
On slippery roads while loaded or empty
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C.
When descending a steep grade
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D.
Heading toward a long downhill
Correct answer: B.
Avoid engine brakes on slippery roads — they can cause the drive wheels to lose traction.
Question 19 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 20 of 25 · Night Driving
When meeting an oncoming vehicle at night, you should:
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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 21 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 22 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 23 of 25 · Hazard Awareness
How can you tell if your truck or bus has a hazardous materials shipment?
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A.
It is moving slowly
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B.
Diamond-shaped placards are displayed
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C.
A flashing yellow light is on
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D.
It is following another truck
Correct answer: B.
Diamond-shaped placards on the vehicle indicate the presence of hazardous materials.
Question 24 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 25 of 25 · Following Distance
Following distance for a heavy vehicle traveling below 40 mph should be at least:
-
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.
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 New Jersey Motor Vehicle Commission administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your New Jersey CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Inspection: 4 questions
- Speed Management: 3 questions
- Backing: 2 questions
- Mountain Driving: 2 questions
- CDL Rules: 2 questions
- Driver Wellness: 2 questions
- Emergency Maneuvers: 1 question
- Hours of Service: 1 question
- Adverse Conditions: 1 question
- Communication: 1 question
- ABS: 1 question
- Rail Crossings: 1 question
- Night Driving: 1 question
- Basic Control: 1 question
- Hazard Awareness: 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 New Jersey 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 New Jersey