Washington Doubles / Triples CDL Practice Test
Below are 25 exam-style questions for the Washington Doubles / Triples CDL knowledge test, modeled on the FMCSA-aligned content used by the Washington State Department of Licensing. 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 Should be driven slowly with extra following distance
- B Can maintain normal speed
- C Should brake hard
- D Should change lanes frequently
- A Has the same rollover risk
- B Is less likely to roll
- C Cannot roll
- D Is more likely to roll than the first
- A Accelerate
- B Reduce speed gradually and avoid sudden steering inputs
- C Brake hard
- D Steer sharply to correct
- A State and federal route restrictions
- B How to inspect each connection point
- C All of the above
- D Coupling and uncoupling procedures
- A Connect a semitrailer to another trailer to form a combination
- B Test the brakes
- C Move cargo within the trailer
- D Replace the fifth wheel on the tractor
- A Skip the air-leak rate check
- B Skip the parking-brake test
- C Skip the brake-light test
- D All of the above
- A Better fuel mileage
- B No change in handling
- C It can sway and lift more easily; drive carefully
- D It is harder to roll over
- A No specific order
- B Reverse of coupling — disconnect rear trailer first, then dolly
- C Disconnect tractor first
- D Random order
- A Speed is reduced faster
- B Tractor cannot jackknife
- C Rear trailer can swing out and cause loss of control
- D Brakes work better
- A Brake hard
- B Steer sharply to correct
- C Reduce speed gradually and avoid sudden steering inputs
- D Accelerate
- A Couple at high speed
- B Skip the lock verification
- C Trust visual inspection only
- D Verify the fifth wheel locks around the kingpin and test by tugging gently
- A Skip the spotter
- B Use only mirrors
- C Avoid backing whenever possible; use a spotter when needed
- D Back at full speed
- A A type of car carrier
- B A combination with a second trailer that has a kingpin attached to the first trailer
- C A type of bus
- D A train carrying buses
- A A bus with two sections
- B Two tractors pulling one trailer
- C Two trailers behind one tractor
- D A trailer with two axles
- A Maintain speed
- B Plan the turn carefully and use multiple lanes if necessary
- C Turn sharply
- D Skip the planning
- A Change at high speed
- B Change quickly without signaling
- C Signal early and change smoothly to minimize swing
- D Change in heavy traffic
- A Skip the air check
- B Allow the dolly to roll freely
- C Couple without verifying
- D Verify the dolly's air tank has air pressure and lock the dolly's parking brake before backing under the second trailer
- A Glad hands and seals at every connection
- B Dolly air-tank pressure
- C All of the above
- D Pintle hooks and safety chains
- A A converter dolly
- B A trailer for transporting animals
- C A short trailer commonly used in doubles and triples
- D A tractor only
- A Increase speed
- B Brake within the curve
- C Maintain speed
- D Slow down before the curve to reduce rollover risk and trailer swing
- A Wind, especially crosswinds and from passing trucks
- B All of the above
- C Cargo placement
- D Lane changes
- A Set parking brakes on the tractor and on the trailers
- B Leave brakes off
- C Set only the tractor parking brake
- D Use the trailer hand valve
- A Trailer length only
- B No specific length
- C Total combination length when turning, parking, and changing lanes
- D Tractor length only
- A Connect it to a random trailer
- B Park it on level ground with the parking brake set or wheels chocked
- C Leave it on a slope
- D Disable the brakes
- A Once a year
- B Before pulling away from the coupling site
- C Never; the dispatcher tests them
- D Only at the destination
Study tips for the Washington Doubles / Triples exam
The Doubles / Triples portion of the Washington CDL exam is graded out of the bank of questions the Washington State Department of Licensing draws from each year. While the exact bank is not published, every question is sourced from the Doubles / Triples chapter of the Washington 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 Washington 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 Washington State Department of Licensing 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 Washington 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 Washington 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 Washington State Department of Licensing office.
Already comfortable with this endorsement? Drill another: WA General Knowledge · WA Air Brakes · WA Combination Vehicles · WA Hazardous Materials · WA Passenger · WA School Bus · WA Tank Vehicle
New to the CDL process in Washington? Read How to apply for a CDL in Washington for the document checklist and step-by-step timeline.