Free CDL Practice Tests · All 50 States + DC · Updated 2026 Official handbooks · CDL pay & outlook
NC · GK Endorsement

North Carolina General Knowledge CDL Practice Test

Below are 25 exam-style questions for the North Carolina General Knowledge CDL knowledge test, modeled on the FMCSA-aligned content used by the North Carolina Division of Motor Vehicles. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.

Heads up: this is a study tool, not a graded exam. Cover the answer with your hand or a sheet of paper for an honest practice run, then re-read the explanations for any questions you missed. Aim for 22 out of 25 or better, three times in a row, before scheduling the real exam.
Question 1 of 25
You are driving on a two-lane road and you see a driver about to pull out from a side road. You should:
  • A Maintain speed
  • B Honk and accelerate
  • C Cover the brake and slow down
  • D Move to the right lane
Correct answer: C
Anticipate the worst-case behavior. Cover the brake — keeping your foot just over it — so you can react if they pull out.
Question 2 of 25
Which is true about communicating in heavy traffic?
  • A Honk loudly to warn other drivers
  • B Never communicate; just drive
  • C Make eye contact only when stopped
  • D Tap the horn lightly or flash lights to signal your presence
Correct answer: D
A light tap of the horn or a brief headlight flash communicates your presence without startling others. A loud, prolonged horn can provoke aggressive responses.
Question 3 of 25
Which of the following is the correct order for the seven-step pre-trip air-brake check (last steps shown)?
  • A Test the service brake then the parking brake
  • B Test the low-air warning then drive
  • C Test only the air-leak rate
  • D Test the parking brake then the service brake
Correct answer: D
In the standard FMCSA seven-step procedure, the parking brake is tested before pulling away, then the service brake stop is the final step.
Question 4 of 25
Skids are most often caused by:
  • A Old tires
  • B Driving too fast for conditions
  • C Manual transmissions
  • D Properly working brakes
Correct answer: B
The dominant cause of skids identified by the FMCSA is driving too fast for the road or weather. Sudden steering, hard braking, or hard acceleration usually triggers them.
Question 5 of 25
Stopping distance is made up of:
  • A Brake-lag distance only
  • B Perception distance + reaction distance + brake-lag distance + braking distance
  • C Reaction distance only
  • D Speed times weight
Correct answer: B
Total stopping distance has four parts. Air brakes add a brake-lag distance not present in hydraulic systems.
Question 6 of 25
You are driving a heavy vehicle and have to stop on a long downgrade. Which is the safest way?
  • A Use a low gear and steady moderate brake application
  • B Disengage the clutch and coast
  • C Use the parking brake to slow down
  • D Pump the brakes hard and fast
Correct answer: A
On a long downgrade, select a low gear before the descent and use steady, light to moderate braking. Hard pumping or coasting in neutral leads to brake fade and loss of control.
Question 7 of 25
You may not drive a CMV with a blood-alcohol concentration of:
  • A 0.04% or higher
  • B 0.08% or higher
  • C 0.10% or higher
  • D Any detectable amount above 0.00%
Correct answer: A
0.04% is the regulatory limit for CMV operation. A detectable amount under that triggers an out-of-service order but is not necessarily a DUI conviction.
Question 8 of 25
A Class C CDL is required to drive:
  • A Class A combinations only
  • B Any vehicle over 26,001 lbs
  • C Vehicles designed to carry 16+ passengers including the driver, or that require hazmat placards
  • D Tractor-trailers under 26,001 lbs GCWR
Correct answer: C
Class C covers vehicles that don't meet Class A or B but are designed to carry 16 or more passengers (including the driver) or carry placarded amounts of hazardous materials.
Question 9 of 25
The two main reasons why a driver's feet are kept off the brakes when not actively braking are:
  • A To rest the right leg
  • B To save brake pads and reduce drag
  • C So the brake lights don't mislead following drivers and so the brakes don't overheat
  • D To save fuel and improve mileage
Correct answer: C
Riding the brake lights confuses drivers behind you and gradually heats the friction surfaces, both of which are safety problems.
Question 10 of 25
A driver should test the parking brake by:
  • A Setting the parking brake, releasing the service brakes, and gently trying to move the vehicle in low gear
  • B Releasing the parking brake on a flat surface and tugging gently against it
  • C Pumping the brakes
  • D Driving over a speed bump
Correct answer: A
The standard test: set parking brakes, gently apply throttle in low gear; if the vehicle moves, the parking brake is not holding.
Question 11 of 25
The minimum tread depth for steer-axle tires is:
  • A 6/32 inch
  • B 4/32 inch
  • C 2/32 inch
  • D 1/32 inch
Correct answer: B
Steer tires must have at least 4/32 inch in every major groove. Other tires require at least 2/32 inch.
Question 12 of 25
Which of the following is NOT part of a pre-trip inspection?
  • A Testing the service and parking brakes
  • B Checking the engine compartment
  • C Walking around the vehicle and checking lights
  • D Adjusting the trailer brakes individually
Correct answer: D
Adjusting brakes is a maintenance task done by qualified personnel, not a pre-trip step. The driver checks for proper operation, not adjustment.
Question 13 of 25
Which of the following is a sign of fatigue?
  • A Drifting in your lane
  • B Trouble remembering the last few miles
  • C All of the above
  • D Frequent yawning
Correct answer: C
All three are classic fatigue indicators in the FMCSA model. Cold air, music, and caffeine are not effective fixes — only sleep is.
Question 14 of 25
A driver may keep moving when:
  • A A trailer brake light is out
  • B A vehicle is in safe operating condition
  • C A passenger door is open
  • D Required emergency equipment is missing
Correct answer: B
Federal rules forbid driving any CMV that is not in safe operating condition. Continue only after the defect is fixed.
Question 15 of 25
What does it mean when a road sign says "Bridge formation may freeze before road"?
  • A The pavement under the bridge is reinforced
  • B Bridge surfaces freeze first because of air circulation underneath
  • C Bridges are inspected only in winter
  • D The bridge is closed in winter
Correct answer: B
Cold air around bridges and overpasses cools the deck more quickly than the surrounding road, which is why ice often appears there first.
Question 16 of 25
Black ice is most likely on:
  • A Roads in direct sunlight
  • B Gravel surfaces
  • C Concrete pavement only
  • D Bridges and overpasses
Correct answer: D
Bridges and overpasses freeze first because cold air circulates above and below them. They are the most-asked test scenario for sudden ice.
Question 17 of 25
Which is true about the use of turn signals?
  • A Signal only when other vehicles are present
  • B Use the four-way flashers instead of signals at intersections
  • C Signal early, signal continuously, and cancel after the turn
  • D Signal only at the moment you start turning
Correct answer: C
The federal model manual specifies signal early, continuously, and cancel after — the same three steps every state CDL test asks about.
Question 18 of 25
When the road is slippery, you should:
  • A Make smooth steering and braking inputs
  • B Slow down
  • C Increase following distance
  • D All of the above
Correct answer: D
Slippery roads require all three: more cushion, smoother inputs, and lower speed.
Question 19 of 25
How does ABS help in an emergency stop?
  • A It always stops the vehicle in a shorter distance
  • B It applies the parking brake
  • C It increases brake pressure automatically
  • D It prevents wheel lockup so the driver can keep steering
Correct answer: D
ABS keeps the wheels rolling so steering control is preserved. It is not a shorter-distance device.
Question 20 of 25
When should you use four-way flashers?
  • A Whenever you feel like it
  • B When you are stopped or moving slowly enough to be a hazard
  • C Only at night
  • D Only on the highway
Correct answer: B
Four-ways are for vehicles stopped on or near the road or moving so slowly that they are a hazard.
Question 21 of 25
Acceleration must be smooth and gradual to avoid:
  • A Powertrain wear and possible loss of control on slippery surfaces
  • B Annoying passengers
  • C Wasting fuel only
  • D Engine damage
Correct answer: A
Quick throttle inputs on slick surfaces can spin the drive wheels and cause a tractor jackknife. Smooth acceleration avoids this and reduces wear.
Question 22 of 25
When approaching a steep downgrade, the basic safe-driving rule is:
  • A Stay in high gear
  • B Use the parking brake intermittently
  • C Coast in neutral
  • D Select a lower gear before starting down
Correct answer: D
Get into a low gear before the descent so the engine helps hold the vehicle back.
Question 23 of 25
A driver convicted of a major offense (DUI, leaving the scene, etc.) in a CMV faces:
  • A A warning
  • B A fine only
  • C No federal consequence
  • D CDL disqualification for at least one year for a first offense
Correct answer: D
Major offenses carry a one-year CDL disqualification minimum (three years if hauling hazardous materials), and lifetime for a second.
Question 24 of 25
To recover from a front-wheel skid, you should:
  • A Brake hard immediately
  • B Release the brake, let the wheels turn freely, and let the vehicle slow down
  • C Accelerate
  • D Steer sharply in the opposite direction
Correct answer: B
A front-wheel skid is usually caused by braking too hard. Release the brake to allow the front tires to grip again so steering returns.
Question 25 of 25
A "wig-wag" is:
  • A A trailer hitch component
  • B A type of cargo strap
  • C A low-air pressure warning device that drops a flag in front of the driver
  • D A fuel-saving switch
Correct answer: C
On older trucks, a wig-wag is a mechanical low-air warning that lowers a flag into the driver's field of view when air pressure drops below safe limits.

Study tips for the North Carolina General Knowledge exam

The General Knowledge portion of the North Carolina CDL exam is graded out of the bank of questions the North Carolina Division of Motor Vehicles draws from each year. While the exact bank is not published, every question is sourced from the General Knowledge chapter of the North Carolina CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.

Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official North Carolina handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.

Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about General Knowledge.

Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The North Carolina Division of Motor Vehicles will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.

Finally, keep your General Knowledge fundamentals sharp even when you're focused on the General Knowledge exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh North Carolina General Knowledge practice test before scheduling the real exam.

Next steps

Missed more than four questions? Re-read the General Knowledge study guide and the matching chapter in the official North Carolina CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local North Carolina Division of Motor Vehicles office.

Already comfortable with this endorsement? Drill another: NC Air Brakes · NC Combination Vehicles · NC Hazardous Materials · NC Passenger · NC School Bus · NC Tank Vehicle · NC Doubles / Triples

New to the CDL process in North Carolina? Read How to apply for a CDL in North Carolina for the document checklist and step-by-step timeline.