North Carolina CDL Combination Test (NC) 2026

4.9 out of 5 (77 votes)
80% Passing score
20 Questions
4 Mistakes allowed
If you're gearing up to obtain your Commercial Driver's License (CDL) combination vehicles endorsement in NC, our North Carolina CDL combination practice test is the perfect tool to help you prepare. This comprehensive test covers all essential areas, from coupling and uncoupling procedures to detailed pre-trip inspections, vital driving techniques, and intricate backing and maneuvering skills. It also delves into air brake systems, ensuring you're well-versed in every aspect of operating combination vehicles safely and efficiently. Our NC CDL combination practice test includes 20 multiple-choice questions, mirroring the format you'll encounter on the actual written permit test. You need to score at least 16 correct answers to pass. This NC driving test practice is designed to reinforce your understanding of the critical topics you'll face, such as the increased stopping distances required for combination vehicles due to their substantial weight. Grasping these concepts is crucial for ensuring road safety and mastering the unique challenges presented by these larger, heavier vehicles. While this combination vehicle test does not replace a state-certified drivers ed or Entry-Level Driver Training (ELDT) course, it serves as a complementary resource. You can use it alongside your formal education to deepen your understanding and improve your confidence in the material. The North Carolina combination CDL practice test is free, providing an invaluable resource without the burden of expensive fees often associated with other practice tests. Despite being free, it offers the same extensive features and study opportunities found in paid versions. The multiple-choice and true or false format of this NC permit test will help you become adept at eliminating incorrect answers and selecting the right ones, a critical skill for the actual test. By practicing with our NC combination CDL practice test, you're setting yourself up for success, ensuring you're well-prepared to handle the demands of combination vehicles on the road.
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Sample North Carolina Combination Test Questions

Question 1

After coupling a tractor and semitrailer, what must be verified about the trailer’s electrical cord?

  1. A It is wrapped around an air line for support
  2. B It is left loose enough to contact the tractor frame
  3. C It is firmly plugged in, secured, and free from damage
  4. D It is disconnected until the air system is fully charged

Correct answer: C – It is firmly plugged in, secured, and free from damage

The trailer electrical cord must be plugged in firmly and secured with its safety catch. The cord should also be inspected for damage and positioned where it cannot contact moving vehicle parts. These checks are part of the coupling procedure and should be completed before the combination is driven.

Source: North Carolina Commercial Driver License Manual — § 6.4.1, “Step 14. Connect the Electrical Cord and Check Air-lines”

Question 2

Which procedure checks whether a semitrailer is locked securely to the tractor?

  1. A Accelerate rapidly with all brakes released
  2. B Turn sharply while watching the trailer
  3. C Raise the landing gear slightly and pull gently forward with the trailer brakes locked
  4. D Release the fifth-wheel locking lever and check the mirrors

Correct answer: C – Raise the landing gear slightly and pull gently forward with the trailer brakes locked

The North Carolina coupling procedure directs the driver to raise the landing gear slightly and gently pull the tractor forward while the trailer brakes remain locked. Resistance confirms that the trailer is locked to the tractor. The driver must then inspect the fifth-wheel jaws, locking lever, safety latch, and the space between the upper and lower fifth wheel.

Source: North Carolina Commercial Driver License Manual — § 6.4.1, “Step 11. Check Connection for Security” and “Step 13. Inspect Coupling”

Question 3

Why must the trailer hand valve not be used to hold a parked combination vehicle?

  1. A Air may leak away and release the brakes on a trailer without spring brakes
  2. B It automatically disconnects the trailer air lines
  3. C It prevents the tractor’s parking brakes from being applied
  4. D It permanently locks the trailer service brakes

Correct answer: A – Air may leak away and release the brakes on a trailer without spring brakes

The trailer hand valve depends on air pressure and is not a parking-brake control. On a trailer without spring brakes, air can eventually leak away and release the brakes, allowing the trailer to move. Use the vehicle’s parking brakes when parking, and use wheel chocks when parking a trailer that has no spring brakes.

Source: North Carolina Commercial Driver License Manual — § 6.2.1, “Trailer Hand Valve”

Question 4

What should you do if the low-air warning activates while driving a combination vehicle?

  1. A Increase engine speed and continue to the next terminal
  2. B Bring the vehicle to a safe stop right away and park safely
  3. C Apply only the trailer hand valve
  4. D Wait for the spring brakes to apply automatically

Correct answer: B – Bring the vehicle to a safe stop right away and park safely

A low-air warning indicates that the system may have a leak or another serious problem. Stop and park safely as soon as possible while enough air remains for controlled braking. Do not wait for the spring brakes to apply automatically; their application at low pressure can produce a long stop or a loss of control.

Source: North Carolina Commercial Driver License Manual — § 5.4.7, “Low Air Pressure”

Question 5

What is the proper use of the trailer hand valve?

  1. A Holding the combination vehicle on a hill
  2. B Parking the trailer overnight
  3. C Controlling the trailer during normal driving
  4. D Testing the trailer brakes

Correct answer: D – Testing the trailer brakes

The trailer hand valve should be used only to test the trailer brakes. Using it during normal driving applies only the trailer brakes and can cause the trailer to skid or jackknife. The foot brake applies the brakes throughout the combination vehicle and presents less danger of producing a skid.

Source: North Carolina Commercial Driver License Manual — § 6.2.1, “Trailer Hand Valve”

Question 6

What can occur if the service and emergency air lines are crossed on an older trailer without spring brakes?

  1. A The combination may move, but the trailer brakes will not work
  2. B The brake pedal will operate only the trailer’s parking brakes
  3. C The hand valve will apply the tractor brakes
  4. D The trailer air tanks will charge normally

Correct answer: A – The combination may move, but the trailer brakes will not work

The North Carolina manual warns that an older trailer without spring brakes may be driven away with crossed air lines, but without functioning trailer brakes. This is extremely dangerous. Before driving, test the trailer brakes by using the hand valve or trailer air-supply control and gently pulling against the applied brakes in a low gear.

Source: North Carolina Commercial Driver License Manual — § 6.2.5, “Hose Couplers (Glad Hands)”

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