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Alaska Doubles / Triples CDL Practice Test

Below are 25 exam-style questions for the Alaska Doubles / Triples CDL knowledge test, modeled on the FMCSA-aligned content used by the Alaska 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
A doubles/triples driver should never:
  • A Back without a spotter when possible
  • B Skip the air-brake check
  • C All of the above
  • D Drive faster than conditions allow
Correct answer: C
All three are violations of safe doubles/triples operation.
Question 2 of 25
When approaching a curve in a doubles combination:
  • A Increase speed
  • B Brake within the curve
  • C Slow down before the curve to reduce rollover risk and trailer swing
  • D Maintain speed
Correct answer: C
Speed reduction before the curve prevents rollover.
Question 3 of 25
When you need to make a lane change in heavy traffic with doubles:
  • A Plan the change well in advance, signal early, and change when there is ample space
  • B Change quickly to fit in
  • C Cut between cars
  • D Skip the signal
Correct answer: A
Planning and patience prevent collisions.
Question 4 of 25
When you turn a combination of doubles or triples right at an intersection:
  • A No off-tracking occurs
  • B Off-tracking is less than a single trailer
  • C Off-tracking is more pronounced; swing wider than for a single trailer
  • D Use the left lane
Correct answer: C
More trailers = more off-tracking; plan turns carefully.
Question 5 of 25
A "coupling device" on a converter dolly:
  • A Is the same as a tractor fifth wheel
  • B Includes a pintle hook on the front and a fifth wheel on the back
  • C Is electrical only
  • D Is a single hook
Correct answer: B
Converter dollies have both ends: pintle hook to attach to the lead trailer, fifth wheel for the trailing trailer's kingpin.
Question 6 of 25
When the converter dolly's tires are damaged:
  • A Replace before operating
  • B Ignore the damage
  • C Continue with damaged tires
  • D Use the spare
Correct answer: A
Damaged tires must be replaced before operation.
Question 7 of 25
A "double" in trucking refers to:
  • A A bus with two sections
  • B Two tractors pulling one trailer
  • C A trailer with two axles
  • D Two trailers behind one tractor
Correct answer: D
Double = two trailers behind one tractor; triple = three trailers.
Question 8 of 25
A converter dolly is used to:
  • A Test the brakes
  • B Connect a semitrailer to another trailer to form a combination
  • C Move cargo within the trailer
  • D Replace the fifth wheel on the tractor
Correct answer: B
Converter dollies turn semitrailers into trailers that can be coupled in series.
Question 9 of 25
A doubles combination requires:
  • A Air lines only on the tractor
  • B No air-brake system
  • C Mechanical brakes only
  • D Air lines from tractor to first trailer to dolly to second trailer
Correct answer: D
Air system extends through the entire combination via glad hands at each connection.
Question 10 of 25
When uncoupling doubles, the order is:
  • A Reverse of coupling — disconnect rear trailer first, then dolly
  • B Disconnect tractor first
  • C Random order
  • D No specific order
Correct answer: A
Reverse coupling order maintains safety throughout.
Question 11 of 25
The trailer hand valve on a doubles/triples combination operates:
  • A Only the first trailer brakes
  • B All trailer service brakes simultaneously
  • C Only the rear trailer brakes
  • D Tractor and trailer brakes
Correct answer: B
Hand valve applies all trailer service brakes; do not use as a parking brake.
Question 12 of 25
When the trailers are properly coupled:
  • A All air lines and electrical lines should be connected and tested
  • B Some lines may be optional
  • C Test only one line
  • D Skip the testing
Correct answer: A
Every connection must be tested before pulling away.
Question 13 of 25
When the second trailer lifts off the road in a turn:
  • A Brake hard
  • B Continue normally
  • C Increase speed
  • D Slow down and reduce steering input — rollover is imminent
Correct answer: D
Lift-off precedes rollover; gentle reduction prevents disaster.
Question 14 of 25
A doubles/triples driver should be especially aware of:
  • A Potential rollover at curves
  • B Lane changes that swing the rear
  • C Crosswind effects on the rear trailer
  • D All of the above
Correct answer: D
All three considerations apply to multi-trailer combinations.
Question 15 of 25
In a doubles combination, the second (rear) trailer:
  • A Is more likely to roll than the first
  • B Cannot roll
  • C Has the same rollover risk
  • D Is less likely to roll
Correct answer: A
Rear trailer in a doubles is the most rollover-prone unit.
Question 16 of 25
When inspecting safety chains:
  • A Verify they are crossed under the pintle hook and not dragging
  • B Skip the inspection
  • C Allow them to drag
  • D Tie them in knots
Correct answer: A
Crossing chains catches the trailer if the hook fails; dragging chains can damage roadway and themselves.
Question 17 of 25
Coupling order for doubles is generally:
  • A Random order
  • B Tractor to second trailer first
  • C Drop first trailer, hook converter dolly to first trailer, back tractor to second trailer, etc.
  • D Trailers first, then tractor
Correct answer: C
Doubles coupling has a specific order to ensure stability and safety.
Question 18 of 25
When uncoupling a converter dolly:
  • A Allow the dolly to roll
  • B Set the parking brake or chock the wheels before disconnecting
  • C Skip the parking brake
  • D Disconnect at high speed
Correct answer: B
Brake setting prevents dolly movement during disconnect.
Question 19 of 25
A doubles/triples driver should always:
  • A Drive as if it were a single trailer
  • B Be aware of the increased complexity of the equipment and operate accordingly
  • C Skip the pre-trip
  • D Use the trailer hand valve as a parking brake
Correct answer: B
Awareness of complexity is essential for safe operation.
Question 20 of 25
A "pup" trailer is:
  • A A short trailer commonly used in doubles and triples
  • B A converter dolly
  • C A trailer for transporting animals
  • D A tractor only
Correct answer: A
"Pup" is the common term for a short trailer used in multi-trailer combinations.
Question 21 of 25
When inspecting doubles or triples, you should check:
  • A Pintle hooks and safety chains
  • B Dolly air-tank pressure
  • C Glad hands and seals at every connection
  • D All of the above
Correct answer: D
Each connection point is a potential failure; check thoroughly.
Question 22 of 25
When you couple the second trailer to the converter dolly:
  • A Couple at high speed
  • B Verify the fifth wheel locks around the kingpin and test by tugging gently
  • C Skip the lock verification
  • D Trust visual inspection only
Correct answer: B
Verification prevents the catastrophic loss of the second trailer.
Question 23 of 25
A driver pulling doubles or triples should drive in:
  • A Any lane
  • B The right lane on multilane highways when possible
  • C The left lane
  • D The shoulder
Correct answer: B
Slower lanes are safer for long combinations.
Question 24 of 25
When the rear trailer of a doubles combination begins to sway:
  • A Steer sharply to correct
  • B Reduce speed gradually and avoid sudden steering inputs
  • C Accelerate
  • D Brake hard
Correct answer: B
Smooth reduction in speed allows the trailer to settle.
Question 25 of 25
A doubles/triples driver should plan routes to:
  • A Avoid freeways
  • B Take the shortest route regardless
  • C Drive only at night
  • D Avoid restricted roads and minimize sharp curves and steep grades
Correct answer: D
Route planning reduces handling demands.

Study tips for the Alaska Doubles / Triples exam

The Doubles / Triples portion of the Alaska CDL exam is graded out of the bank of questions the Alaska 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 Alaska 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 Alaska 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 Alaska 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 Alaska 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 Alaska 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 Alaska Division of Motor Vehicles office.

Already comfortable with this endorsement? Drill another: AK General Knowledge · AK Air Brakes · AK Combination Vehicles · AK Hazardous Materials · AK Passenger · AK School Bus · AK Tank Vehicle

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