Hawaii CDL Combination Test (HI) 2026

4.9 out of 5 (36 votes)
80% Passing score
20 Questions
4 Mistakes allowed
Prepare for your Commercial Driver's License (CDL) combination vehicles endorsement with our comprehensive Hawaii permit test practice. This invaluable resource is designed to help you master the critical areas essential for safe and efficient driving of combination vehicles. The questions are meticulously crafted based on the official driver's manual, ensuring that you're studying the same material that will appear on the actual DMV test. With our Hawaii DMV practice test, you can study confidently, knowing that all the information you need is sourced directly from the state's handbook. Our practice permit test is available online around the clock, allowing you the flexibility to study whenever it suits your schedule. Unlike traditional driving schools, which require you to adhere to their timing, you can take our Hawaii permit practice test at your convenience. Whether you're an early bird or a night owl, our platform is always accessible, ready to support your study needs. While this CDL combination test is not a substitute for a state-certified driver's education or ELDT course, it serves as an excellent supplement. You can use it alongside your formal education to deepen your understanding of the material. The Hawaii combination vehicle test covers a broad range of topics, including coupling and uncoupling procedures, pre-trip inspections, driving techniques, backing and maneuvering, and air brake systems. Each Hawaii combination CDL practice test consists of 20 multiple-choice questions, with a minimum of 16 correct answers required to pass. This rigorous preparation helps ensure that you can handle the increased stopping distances and other unique challenges of operating larger, heavier vehicles. By focusing on these critical areas, our Hawaii combination CDL practice test prepares you to maintain safety on the road and meet the demands of your CDL combination vehicle endorsement. Start today with our comprehensive practice test and move one step closer to achieving your CDL combination vehicle endorsement. Remember, consistent practice and a solid understanding of the material are key to your success.
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Sample Hawaii Combination Test Questions

Question 1

Why should cargo in a combination vehicle be kept as low as practical?

  1. A It lowers the center of gravity and reduces rollover risk
  2. B It makes every part of the load easier to reach
  3. C It guarantees lower fuel consumption
  4. D It eliminates tire wear caused by heavy loads

Correct answer: A – It lowers the center of gravity and reduces rollover risk

The Hawaii CDL Driver’s Manual identifies keeping cargo close to the ground as an important way to prevent rollovers. Raising the load raises the vehicle’s center of gravity, making the vehicle easier to overturn. The load should also be centered and distributed as evenly as practical because a trailer leaning to one side has greater rollover risk.

Source: Hawaii CDL Driver’s Manual — § 6.1.1, “Rollover Risks”

Question 2

What should you do if braking locks the trailer wheels and starts a trailer skid?

  1. A Accelerate until the trailer straightens
  2. B Steer sharply away from the trailer
  3. C Apply the trailer hand brake harder
  4. D Release the brakes to restore traction

Correct answer: D – Release the brakes to restore traction

Release the brakes to let the trailer wheels roll and regain traction. Locked trailer wheels can cause the trailer to swing outward into a trailer jackknife. Do not apply the trailer hand brake to straighten the combination because braking the trailer caused the wheels to lose traction in the first place.

Source: Hawaii CDL Driver’s Manual — § 6.1.5, “Prevent Trailer Skids”

Question 3

What can happen if a trailer is positioned too low before the tractor backs under it?

  1. A The fifth wheel will automatically raise the trailer without risk
  2. B The air lines cannot be connected
  3. C The tractor may strike and damage the trailer nose
  4. D The trailer brakes will release

Correct answer: C – The tractor may strike and damage the trailer nose

Before completing the coupling, check that the trailer is low enough to be raised slightly as the tractor backs under it. A trailer that is too low may be struck by the tractor, damaging the trailer nose. A trailer that is too high presents a different problem because the fifth wheel may not couple correctly with the kingpin.

Source: Hawaii CDL Driver’s Manual — § 6.4.1, “Step 6. Check Trailer Height”

Question 4

Compared with single-unit commercial vehicles, combination vehicles are generally heavier, longer, and more demanding to operate.

  1. A TRUE
  2. B FALSE

Correct answer: A – TRUE

The statement is true. The Hawaii CDL Driver’s Manual explains that combination vehicles are generally heavier and longer and require greater driving skill than single commercial vehicles. Their drivers need additional knowledge to manage concerns such as rollover risk, trailer skids, off-tracking, braking, and coupling.

Source: Hawaii CDL Driver’s Manual — § 6.1, “Driving Combination Vehicles Safely”

Question 5

What is the function of a combination vehicle’s service air line?

  1. A It supplies air that keeps the trailer parking brakes applied
  2. B It sends compressed air to cool the tractor cab
  3. C It carries control pressure to relay valves that apply the trailer brakes
  4. D It supplies air directly to the trailer reservoirs

Correct answer: C – It carries control pressure to relay valves that apply the trailer brakes

The service line is also called the control or signal line. Its pressure changes according to the driver’s use of the foot brake or trailer hand valve. That pressure signals relay valves, which send air from the trailer tanks to the brakes and allow the trailer brakes to apply quickly.

Source: Hawaii CDL Driver’s Manual — § 6.2.4, “Trailer Air-lines”

Question 6

With the engine off and brakes released, a combination vehicle’s air-loss rate should be less than how many psi per minute?

  1. A 1 psi
  2. B 2 psi
  3. C 3 psi
  4. D 4 psi

Correct answer: C – 3 psi

For the released-brake leakage test, first charge the system to governor cutout, shut off the engine, and release the parking brakes. The pressure loss should be less than three psi in one minute for a combination vehicle. The corresponding limit for a single vehicle is less than two psi per minute.

Source: Hawaii CDL Driver’s Manual — § 5.3.3, “Test Air Leakage Rate”

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