Free New Jersey DMV CDL — General Knowledge Practice Test 2026
The New Jersey CDL — General Knowledge knowledge test has ~50 questions, and you need ~40 correct (80%) to pass. Practice free with questions written from the official New Jersey driver handbook — every one has a clear explanation, and you can retake as often as you like with no sign-up.
Content reviewed against official driver handbooks · August 12, 2026
What's on the New Jersey written test
The New Jersey CDL — General Knowledge knowledge test has ~50 questions; you need ~40 correct (80%) to pass.
Based on the official New Jersey exam format — always confirm current details with your state DMV.
Practice by topic
Focus on one area at a time — each topic has its own set of New Jersey practice questions.
Learn the shapes, colors, and meanings of regulatory, warning, and guide signs — from stop and yield to construction and school-zone signs.
Speed limits, turning and signaling rules, headlight and seat-belt requirements, and the everyday laws every driver must follow.
How to read traffic signals, lane lines, and pavement markings — including yellow and white lines, arrows, and flashing lights.
Who goes first at intersections, four-way stops, roundabouts, and crosswalks, and how to yield to pedestrians and emergency vehicles.
Following distance, scanning, blind spots, using your lights, and the habits that prevent crashes and keep you in control.
Driving safely around motorcycles, bicycles, large trucks, pedestrians, and school buses — and knowing who has the right of way.
Blood alcohol limits, zero-tolerance and implied-consent laws, and how alcohol and drugs — legal or not — affect your driving.
Legal and illegal parking, colored curbs, distances from hydrants and crossings, and how to park safely on hills.
Choosing a safe speed, keeping a space cushion, adjusting for weather and traffic, and understanding stopping distance.
What to do when things go wrong — brake failure, tire blowouts, skids, and stalling on railroad tracks.
The point system, license suspension, provisional-license rules, insurance requirements, and other licensing basics.
How to pass the first time
- Read the official New Jersey driver handbook at least once before test day.
- Practice by topic to find your weak spots, then fix them.
- Take full-length practice tests until you pass comfortably every time.
- Read every explanation — understanding beats memorizing.
New Jersey CDL — General Knowledge test — frequently asked questions
How many questions are on the New Jersey CDL — General Knowledge test?
The New Jersey CDL — General Knowledge knowledge test has ~50 questions, and you need ~40 correct (80%) to pass. Our practice tests mirror that format.
How many questions can I miss on the New Jersey CDL — General Knowledge test?
You can miss up to ~10 of the ~50 questions and still pass — you need ~40 correct, which is 80%.
Can I retake the practice test?
Yes — practice as often as you like, completely free. The questions and answer choices are shuffled each time.
Can I take the New Jersey practice test in Spanish?
Yes. Every question here is available in English and Spanish — switch languages anytime. Many states also offer the real knowledge test in languages other than English; confirm what New Jersey offers with your DMV.
Can I practice on my phone?
Yes. The practice tests work in any mobile or desktop browser — no app or sign-up needed — so you can study anywhere.
Are these the real DMV test questions?
No. Our questions are original, written from the current official New Jersey driver handbook to match the real test's topics and style. We are not affiliated with any DMV or government agency.
What's the best way to study?
Read the New Jersey driver handbook, practice by topic to target weak areas, and finish with full-length tests until you consistently pass.
Other New Jersey practice tests
Take the CDL — General Knowledge test in another state
Every New Jersey question is written from the official New Jersey driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free
New Jersey CDL — General Knowledge questions with answers
20 sample questions from the New Jersey CDL — General Knowledge question bank — each with the correct answer, a short explanation, and the section of the official handbook it comes from.
Show all 20 questions with answers
1. Why should you never remove a radiator cap or open the pressurized cooling system while the engine is hot?
Correct answer: Steam and boiling water can spray out and burn you
Steam and boiling water can spray out under pressure and cause severe burns; wait until the system has cooled before opening it.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Engine Coolant)
2. Which part of the brain does alcohol affect first as blood alcohol concentration builds?
Correct answer: The part controlling judgment and self-control
Alcohol first affects the part of the brain that controls judgment and self-control, which can keep drinkers from realizing they are getting drunk.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Alcohol and the Brain)
3. Federal regulations regarding text messaging while operating a commercial motor vehicle state what?
Correct answer: Texting is banned while driving the vehicle
Sending or reading text messages while driving a CMV is prohibited; carriers also may not require or permit their drivers to text behind the wheel.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Texting)
4. A four-digit identification number shown on an orange panel on a tank vehicle is used mainly for what purpose?
Correct answer: To let first responders identify the hazardous material
The four-digit code lets emergency responders quickly identify the material being hauled by looking it up in the Emergency Response Guidebook.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Lists of Regulated Products)
5. If a move-over lane change is not safe when approaching a roadside emergency vehicle, what should you do instead?
Correct answer: Slow down and proceed carefully at a safe speed
When changing lanes would be unsafe, slow down and proceed with caution at a speed safe for the traffic conditions.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Move-Over Laws)
6. For a first railroad-highway grade crossing violation, how long will a CDL holder lose their license?
Correct answer: At least 60 days
A first grade-crossing violation costs at least 60 days; a second within three years costs at least 120 days, and a third within three years at least one year.
Source: New Jersey CDL Manual — Section 1: Introduction (Railroad-highway Grade Crossing Violations)
7. What is an escape ramp designed to do?
Correct answer: Safely stop a runaway vehicle whose brakes have failed
Escape ramps use a long bed of soft material, sometimes on an upgrade, to safely stop a runaway vehicle without injuring the driver.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Brake Failure on Downgrades)
8. At night, why are your turn signals and brake lights considered even more important than in daytime?
Correct answer: They are the main way to tell other drivers your intentions
In darkness these lights become the main way of telling other drivers what you plan to do, so they must be clean and working.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Vehicle Factors)
9. When you see a delivery truck such as a step van or postal vehicle, what hazard should you anticipate?
Correct answer: The driver may suddenly step out or pull into the traffic lane
Delivery drivers are often in a hurry, with vision blocked by packages or open doors, and may suddenly step out or pull into traffic.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Delivery Trucks Can Present a Hazard)
10. On packed snow, by how much should you cut your speed?
Correct answer: By half or more
On packed snow, reduce your speed by half or more; if the surface turns icy, slow to a crawl and stop as soon as you safely can.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Matching Speed to the Road Surface)
11. When you back a commercial vehicle, which reverse gear should you use and at what speed?
Correct answer: The lowest reverse gear, moving as slowly as possible
Back as slowly as possible in the lowest reverse gear so you can correct steering errors easily and stop quickly if needed.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Backing Safely)
12. Which headlights should you use in fog, even during daylight hours?
Correct answer: Low-beam headlights and fog lights
Use low-beam headlights (and fog lights if equipped) in fog; high beams reflect off the fog and reduce your visibility.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Driving in Fog)
13. Besides judgment, what abilities does alcohol impair that are critical to driving?
Correct answer: Coordination, reaction speed, depth judgment, and night sight
Drinking degrades coordination of the muscles, slows reactions, distorts depth judgment, and weakens night sight, and for some a single drink already shows impairment.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Alcohol and Driving)
14. A hazardous materials endorsement requires which additional step beyond passing the written test?
Correct answer: A TSA background check with fingerprinting
To earn the hazmat endorsement, an applicant must submit fingerprints and clear a Transportation Security Administration background check.
Source: New Jersey CDL Manual — Section 1: Introduction (Hazardous Materials Endorsement Background Check)
15. A roadside sign reading 'Maximum Safe Speed' before a long downgrade tells a commercial driver what?
Correct answer: You must never go faster than the speed shown
Where a maximum-safe-speed figure is posted for a grade, the driver must never travel faster than the number shown on that sign.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Speed on Downgrades)
16. Which vehicles are always required to stop at a railroad-highway crossing even when no train is visible?
Correct answer: Passenger and placarded hazmat vehicles
All passenger-carrying and placarded hazardous-materials vehicles must stop at these crossings, then check that the tracks are clear.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Warning Signs and Devices)
17. How long will you lose your CDL for committing two serious traffic violations in a CMV within a three-year period?
Correct answer: At least 60 days
Two serious traffic violations within three years cost you the CDL for at least 60 days; three or more within three years cost at least 120 days.
Source: New Jersey CDL Manual — Section 1: Introduction (Serious Traffic Violations)
18. After steering quickly around an obstacle, what must you be ready to do?
Correct answer: Counter-steer back in the other direction
You must be prepared to counter-steer — turn the wheel back the other way once you've passed the obstacle — treating the swerve and counter-steer as one action.
Source: New Jersey CDL Manual — Section 2: Driving Safely (How to Turn Quickly and Safely)
19. On a divided or one-way highway, where must you place your three warning devices after stopping?
Correct answer: At 10, 100, and 200 feet toward approaching traffic
On a one-way or divided highway, set the triangles at about 10 feet, 100 feet, and 200 feet from the vehicle toward the approaching traffic.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Communicating Your Presence)
20. What clues may tell you a driver ahead is a confused tourist unfamiliar with the area?
Correct answer: Roof luggage, out-of-state plates, and sudden stops or lane changes
Roof-top luggage, out-of-state plates, sudden stops, unexplained lane changes, and hesitation are clues to a confused or unfamiliar driver.
Source: New Jersey CDL Manual — Section 2: Driving Safely (Confused Drivers)