Hawaii Combination Vehicles CDL Practice Test
Below are 25 exam-style questions for the Hawaii Combination Vehicles CDL knowledge test, modeled on the FMCSA-aligned content used by the Hawaii Department of Transportation. 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 Trailer sway in crosswinds
- B All of the above
- C Off-tracking on right turns
- D Reduced visibility along the trailer
- A Test the trailer brakes
- B Apply trailer brakes momentarily
- C Both for parking and to prevent jackknife
- D Hold the vehicle when parking
- A Lane positioning at intersections
- B Cargo placement
- C The fuel mileage
- D The trailer following the same path as the tractor in a straight line
- A Are normal until the lining is gone
- B Only need attention every 5 years
- C Make the truck quieter
- D Should be replaced when worn beyond manufacturer specs
- A Brake fade
- B Wheel damage
- C Off-tracking — the trailer wheels follow a tighter arc than the tractor
- D No off-tracking
- A Empty
- B Properly chocked
- C Loaded
- D Too high — it can damage the kingpin or skip over the fifth wheel
- A Coupling devices for connecting tractor air lines to the trailer
- B Electrical connectors
- C Brake adjustment levers
- D Manual transmission shifters
- A Cargo movement
- B Worn out tires
- C Driving too fast for conditions and/or too closely
- D Engine failure
- A Two car lengths
- B One second per 10 feet of vehicle length below 40 mph, plus one extra second above 40 mph
- C A vehicle length
- D No specific rule
- A No effect
- B Small trailer movement
- C Loss of brake pressure
- D Large trailer angle changes; small inputs are key
- A Can be detected during pre-trip inspection by visual and pressure checks
- B Are caused by low fuel
- C Show up only at high speed
- D Need a mechanic to find
- A The parking brake
- B The tractor service brakes only
- C The trailer service brakes only
- D Both tractor and trailer brakes simultaneously
- A Is part of the tractor
- B Is used only when triple-towing
- C Is used to convert a semitrailer into a full trailer for towing in combination
- D Replaces the fifth wheel on the tractor
- A Roll over before sliding
- B Stop suddenly
- C Spin out
- D Lose engine power
- A Be open
- B Be loose
- C Be missing
- D Be closed around the shank of the kingpin (not on the head)
- A Use the shoulder
- B Stop traffic by signaling left
- C Turn from the left lane
- D Stay in the right lane and swing the front of the tractor wide enough to clear the curb without inviting cars to pass on the right
- A Drains the trailer reservoir
- B Carries electrical power
- C Sends supply air to the trailer reservoirs
- D Sends air pressure to apply trailer service brakes
- A The drive wheels lose traction and the tractor begins to slide
- B The fifth wheel disengages
- C The trailer is too heavy
- D The tractor parking brake fails
- A Lowered to the ground while driving
- B Disconnected before driving
- C Fully raised before driving
- D Always halfway extended
- A ABS prevents jackknife in all cases
- B Brake balance is irrelevant
- C Drive wheels never lock
- D Trailer wheels lock more often than drive wheels in panic stops
- A Carries electrical signals
- B Sends supply air to the trailer reservoirs and controls the trailer emergency brakes
- C Operates the parking brake only
- D Drains the wet tank
- A Drive away immediately
- B Pump the brakes 10 times
- C Drain the wet tank
- D Charge the trailer brakes by setting the trailer air supply control
- A The trailer wheels lock briefly
- B You are driving slowly
- C The drive wheels lock and the trailer pushes the tractor sideways
- D The brakes are released gently
- A Air leakage in the supply line, low pressure, or a brake-balance issue
- B Driver fatigue
- C Cargo placement
- D Engine wear
- A It is illegal in some states
- B It is fine if you are careful
- C It can damage the cab and the trailer (cab corner crush)
- D It is the standard procedure
Study tips for the Hawaii Combination Vehicles exam
The Combination Vehicles portion of the Hawaii CDL exam is graded out of the bank of questions the Hawaii Department of Transportation draws from each year. While the exact bank is not published, every question is sourced from the Combination Vehicles chapter of the Hawaii 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 Hawaii 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 Combination Vehicles.
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 Hawaii Department of Transportation 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 Combination Vehicles 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 Hawaii General Knowledge practice test before scheduling the real exam.
Next steps
Missed more than four questions? Re-read the Combination Vehicles study guide and the matching chapter in the official Hawaii 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 Hawaii Department of Transportation office.
Already comfortable with this endorsement? Drill another: HI General Knowledge · HI Air Brakes · HI Hazardous Materials · HI Passenger · HI School Bus · HI Tank Vehicle · HI Doubles / Triples
New to the CDL process in Hawaii? Read How to apply for a CDL in Hawaii for the document checklist and step-by-step timeline.