Louisiana Doubles / Triples CDL Practice Test
Below are 25 exam-style questions for the Louisiana Doubles / Triples CDL knowledge test, modeled on the FMCSA-aligned content used by the Louisiana Office 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 Only on Interstate 80
- B In Canada only
- C On all U.S. highways
- D In some states; restrictions vary
- A Carry electrical signals
- B Provide a backup connection in case the primary coupling fails
- C Are required only on triples
- D Are decorative
- A Last (furthest from the tractor)
- B In the middle
- C It does not matter
- D First (closest to the tractor)
- A A train carrying buses
- B A type of bus
- C A type of car carrier
- D A combination with a second trailer that has a kingpin attached to the first trailer
- A All trailer service brakes simultaneously
- B Only the rear trailer brakes
- C Only the first trailer brakes
- D Tractor and trailer brakes
- A Connect it to a random trailer
- B Disable the brakes
- C Leave it on a slope
- D Park it on level ground with the parking brake set or wheels chocked
- A Increased rollover risk in curves
- B Crosswind sensitivity
- C All of the above
- D Reduced visibility around the second trailer
- A Increase speed
- B Slow down and reduce steering input — rollover is imminent
- C Brake hard
- D Continue normally
- A The converter dolly
- B The first trailer
- C The tractor
- D The rear trailer
- A All of the above
- B Coupling and uncoupling procedures
- C How to inspect each connection point
- D State and federal route restrictions
- A Verify they are crossed under the pintle hook and not dragging
- B Tie them in knots
- C Allow them to drag
- D Skip the inspection
- A The shoulder
- B Any lane
- C The left lane
- D The right lane on multilane highways when possible
- A Dolly air-tank pressure
- B Pintle hooks and safety chains
- C Glad hands and seals at every connection
- D All of the above
- A Speed is reduced faster
- B Brakes work better
- C Tractor cannot jackknife
- D Rear trailer can swing out and cause loss of control
- A Ignore the damage
- B Replace before operating
- C Continue with damaged tires
- D Use the spare
- A Air lines, electrical lines, and connection points
- B Fuel tanks
- C Drivers
- D Engines
- A Couple at high speed
- B Trust visual inspection only
- C Skip the lock verification
- D Verify the fifth wheel locks around the kingpin and test by tugging gently
- A Trailer length only
- B No specific length
- C Total combination length when turning, parking, and changing lanes
- D Tractor length only
- A It accelerates faster
- B Total length and weight increase stopping distance and require more reaction time
- C It uses different brakes
- D It is shorter
- 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
- A Allow chains to drag
- B Skip the safety chains
- C Allow loose engagement
- D Verify it is properly engaged and safety chains are attached
- A Brake within the curve
- B Maintain speed
- C Increase speed
- D Slow down before the curve to reduce rollover risk and trailer swing
- A Turn sharply
- B Plan the turn carefully and use multiple lanes if necessary
- C Skip the planning
- D Maintain speed
- A Before pulling away from the coupling site
- B Only at the destination
- C Once a year
- D Never; the dispatcher tests them
- A Back without a spotter when possible
- B All of the above
- C Skip the air-brake check
- D Drive faster than conditions allow
Study tips for the Louisiana Doubles / Triples exam
The Doubles / Triples portion of the Louisiana CDL exam is graded out of the bank of questions the Louisiana Office 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 Louisiana 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 Louisiana 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 Louisiana Office 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 Louisiana 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 Louisiana 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 Louisiana Office of Motor Vehicles office.
Already comfortable with this endorsement? Drill another: LA General Knowledge · LA Air Brakes · LA Combination Vehicles · LA Hazardous Materials · LA Passenger · LA School Bus · LA Tank Vehicle
New to the CDL process in Louisiana? Read How to apply for a CDL in Louisiana for the document checklist and step-by-step timeline.