North Carolina Doubles / Triples CDL Practice Test
Below are 25 exam-style questions for the North Carolina Doubles / Triples 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.
- A Brakes are uneven
- B Only the rear trailer brakes
- C All trailers should brake together if the system is functioning correctly
- D Only the first trailer brakes
- A Restrictions apply only to hazmat
- B There are no restrictions
- C Federal and state rules vary; T endorsement does not override route restrictions
- D T endorsement allows triples everywhere
- A Any lane
- B The right lane on multilane highways when possible
- C The shoulder
- D The left lane
- A Is a single hook
- B Includes a pintle hook on the front and a fifth wheel on the back
- C Is electrical only
- D Is the same as a tractor fifth wheel
- A All of the above
- B Skip the air-leak rate check
- C Skip the parking-brake test
- D Skip the brake-light test
- A A loose load shifting
- B The rear trailer swinging more than the tractor in turns or lane changes
- C A driver punishing the truck
- D A tire blowout
- A Reduce speed gradually and avoid sudden steering inputs
- B Steer sharply to correct
- C Accelerate
- D Brake hard
- A Increased rollover risk in curves
- B Crosswind sensitivity
- C Reduced visibility around the second trailer
- D All of the above
- A Random order
- B Reverse of coupling — disconnect rear trailer first, then dolly
- C No specific order
- D Disconnect tractor first
- A Verify the dolly's air tank has air pressure and lock the dolly's parking brake before backing under the second trailer
- B Skip the air check
- C Allow the dolly to roll freely
- D Couple without verifying
- A Avoid it; if necessary, uncouple to a single trailer first
- B Have a passenger guide you
- C Back at full speed
- D Use only mirrors
- A Slow down and reduce steering input — rollover is imminent
- B Brake hard
- C Continue normally
- D Increase speed
- A Ignore the damage
- B Replace before operating
- C Continue with damaged tires
- D Use the spare
- A Be aware of the increased complexity of the equipment and operate accordingly
- B Use the trailer hand valve as a parking brake
- C Drive as if it were a single trailer
- D Skip the pre-trip
- A All of the above
- B Lane changes that swing the rear
- C Potential rollover at curves
- D Crosswind effects on the rear trailer
- A Carry electrical signals
- B Are required only on triples
- C Are decorative
- D Provide a backup connection in case the primary coupling fails
- A Change at high speed
- B Change in heavy traffic
- C Signal early and change smoothly to minimize swing
- D Change quickly without signaling
- A The first trailer
- B The converter dolly
- C The tractor
- D The rear trailer
- A Allow loose engagement
- B Allow chains to drag
- C Verify it is properly engaged and safety chains are attached
- D Skip the safety chains
- A Leave brakes off
- B Set only the tractor parking brake
- C Set parking brakes on the tractor and on the trailers
- D Use the trailer hand valve
- A Cannot roll
- B Is more likely to roll than the first
- C Is less likely to roll
- D Has the same rollover risk
- A Set the parking brake or chock the wheels before disconnecting
- B Skip the parking brake
- C Disconnect at high speed
- D Allow the dolly to roll
- A Should brake hard
- B Should change lanes frequently
- C Should be driven slowly with extra following distance
- D Can maintain normal speed
- A All trailer service brakes simultaneously
- B Only the first trailer brakes
- C Only the rear trailer brakes
- D Tractor and trailer brakes
- A A bus with two sections
- B Two tractors pulling one trailer
- C Two trailers behind one tractor
- D A trailer with two axles
Study tips for the North Carolina Doubles / Triples exam
The Doubles / Triples 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 Doubles / Triples 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 Doubles / Triples.
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 Doubles / Triples 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 Doubles / Triples 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 General Knowledge · NC Air Brakes · NC Combination Vehicles · NC Hazardous Materials · NC Passenger · NC School Bus · NC Tank Vehicle
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.