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HI · GK Endorsement

Hawaii General Knowledge CDL Practice Test

Below are 25 exam-style questions for the Hawaii General Knowledge 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.

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
Which is true about driving in fog?
  • A Use low-beam headlights and slow down
  • B Drive faster to get out of the fog quickly
  • C Use the four-ways while in motion at highway speed
  • D Use high-beam headlights for maximum visibility
Correct answer: A
High beams reflect off fog and reduce visibility. Slow down and use low beams or fog lamps if equipped.
Question 2 of 25
A leaking exhaust system is dangerous because:
  • A It can let poisonous carbon monoxide into the cab
  • B It is illegal
  • C It causes the engine to overheat
  • D It increases fuel use
Correct answer: A
Carbon monoxide from a leaking exhaust can cause headaches, drowsiness, and unconsciousness. The illegality is real but the safety risk is the bigger answer.
Question 3 of 25
What does GVWR stand for?
  • A Gross Vehicle Weight Rating
  • B Government Vehicle Weight Regulation
  • C General Vehicle Weight Reading
  • D Gross Vehicle Width Rating
Correct answer: A
GVWR is the maximum weight the manufacturer says a single vehicle can safely weigh, including itself plus its load.
Question 4 of 25
You are driving a heavy vehicle and have to stop on a long downgrade. Which is the safest way?
  • A Use a low gear and steady moderate brake application
  • B Disengage the clutch and coast
  • C Pump the brakes hard and fast
  • D Use the parking brake to slow down
Correct answer: A
On a long downgrade, select a low gear before the descent and use steady, light to moderate braking. Hard pumping or coasting in neutral leads to brake fade and loss of control.
Question 5 of 25
A CDL is required to operate a single vehicle with a GVWR of:
  • A 40,000 lbs or more
  • B 10,001 lbs or more
  • C 26,001 lbs or more
  • D 20,000 lbs or more
Correct answer: C
Single vehicles at or above 26,001 lbs GVWR (Class B) require a CDL. Class A applies to combinations at or above 26,001 lbs GCWR with a trailer over 10,000 lbs.
Question 6 of 25
What does it mean when a road sign says "Bridge formation may freeze before road"?
  • A Bridge surfaces freeze first because of air circulation underneath
  • B The pavement under the bridge is reinforced
  • C The bridge is closed in winter
  • D Bridges are inspected only in winter
Correct answer: A
Cold air around bridges and overpasses cools the deck more quickly than the surrounding road, which is why ice often appears there first.
Question 7 of 25
A driver should test the parking brake by:
  • A Releasing the parking brake on a flat surface and tugging gently against it
  • B Pumping the brakes
  • C Driving over a speed bump
  • D Setting the parking brake, releasing the service brakes, and gently trying to move the vehicle in low gear
Correct answer: D
The standard test: set parking brakes, gently apply throttle in low gear; if the vehicle moves, the parking brake is not holding.
Question 8 of 25
Which is true about the use of turn signals?
  • A Signal only when other vehicles are present
  • B Use the four-way flashers instead of signals at intersections
  • C Signal only at the moment you start turning
  • D Signal early, signal continuously, and cancel after the turn
Correct answer: D
The federal model manual specifies signal early, continuously, and cancel after — the same three steps every state CDL test asks about.
Question 9 of 25
The maximum allowable on-duty driving time after 8 consecutive hours off duty is:
  • A 14 hours
  • B 11 hours
  • C 16 hours
  • D 10 hours
Correct answer: B
After 10 hours off duty, a property-carrying driver may drive up to 11 hours, within a 14-hour on-duty window.
Question 10 of 25
Which is true about brake lining wear and adjustment?
  • A Drum brakes never need adjustment
  • B Brakes self-adjust forever
  • C Brake adjustment is the dispatcher's responsibility
  • D Slack adjusters need periodic checking; pushrod travel beyond limits is out-of-service
Correct answer: D
Slack adjusters can fail, and pushrod travel must be within limits. Drivers check; adjustment itself is a maintenance task for qualified personnel.
Question 11 of 25
Which is required when stopping on the side of a level, straight, two-lane road?
  • A Three reflective triangles: 10 ft, 100 ft, and 200 ft toward approaching traffic
  • B One reflective triangle within 10 feet
  • C A flare burning constantly
  • D A spotter walking 1,000 ft up the road
Correct answer: A
On a level straight road, place triangles 10 feet behind the vehicle, 100 feet, and 200 feet to the rear in the direction of approaching traffic.
Question 12 of 25
Stab braking is used:
  • A On vehicles without ABS, to keep them straight in an emergency
  • B To save fuel
  • C On wet roads only
  • D On vehicles with ABS
Correct answer: A
Stab braking — full application then release as soon as wheels lock, then re-apply — is for non-ABS vehicles. With ABS, do not pump.
Question 13 of 25
When backing a heavy vehicle, you should:
  • A Back to the right whenever possible
  • B Use a helper and walk around the vehicle first
  • C Back fast to get it over with
  • D Back without using mirrors so you can watch out the window
Correct answer: B
Always GOAL — Get Out And Look — and use a helper. Backing to the left when possible is preferred because you can see better, not to the right.
Question 14 of 25
When should you use four-way flashers?
  • A When you are stopped or moving slowly enough to be a hazard
  • B Only at night
  • C Whenever you feel like it
  • D Only on the highway
Correct answer: A
Four-ways are for vehicles stopped on or near the road or moving so slowly that they are a hazard.
Question 15 of 25
Which is true about communicating in heavy traffic?
  • A Never communicate; just drive
  • B Tap the horn lightly or flash lights to signal your presence
  • C Honk loudly to warn other drivers
  • D Make eye contact only when stopped
Correct answer: B
A light tap of the horn or a brief headlight flash communicates your presence without startling others. A loud, prolonged horn can provoke aggressive responses.
Question 16 of 25
On a long downgrade, why is it dangerous to use the brakes too much?
  • A It cools the brakes too much
  • B It wastes brake pads
  • C It triggers the ABS warning light
  • D Brake fade can leave you with reduced or no braking power
Correct answer: D
Heat from continuous braking causes the friction surfaces to lose their grip. Use a low gear and brief, moderate brake applications.
Question 17 of 25
A driver must report any accident involving a CMV to the carrier within:
  • A 1 hour
  • B 7 days
  • C 24 hours
  • D A reasonable time, before going off duty
Correct answer: D
FMCSA rules require notification of the motor carrier in a reasonable time — most policies treat that as before going off duty.
Question 18 of 25
When the road is slippery, you should:
  • A All of the above
  • B Increase following distance
  • C Make smooth steering and braking inputs
  • D Slow down
Correct answer: A
Slippery roads require all three: more cushion, smoother inputs, and lower speed.
Question 19 of 25
A vehicle's "no-zone" is:
  • A A federal speed restriction
  • B The area in front of the steer axle
  • C The fuel tank area
  • D The area immediately next to it where other drivers are hidden in your blind spots
Correct answer: D
No-zones are the four blind-spot areas (front, rear, and both sides) where smaller vehicles are difficult or impossible to see in your mirrors.
Question 20 of 25
Hydroplaning is most likely when:
  • A Tires are over-inflated
  • B Tires lose contact with the road on a film of water
  • C Roads are dry but hot
  • D You brake hard on dry pavement
Correct answer: B
Hydroplaning happens when tires ride on top of standing water at speed. Reduce risk by slowing down, keeping tires properly inflated and tread depth adequate.
Question 21 of 25
Stopping distance is made up of:
  • A Perception distance + reaction distance + brake-lag distance + braking distance
  • B Brake-lag distance only
  • C Reaction distance only
  • D Speed times weight
Correct answer: A
Total stopping distance has four parts. Air brakes add a brake-lag distance not present in hydraulic systems.
Question 22 of 25
When approaching a railroad crossing in a CMV that is not required to stop, you should:
  • A Honk and proceed
  • B Slow down, look, listen, and be prepared to stop
  • C Cross at maximum speed to get over quickly
  • D Always come to a full stop regardless of traffic
Correct answer: B
Even when not required by class to stop, you must always be prepared to stop. Buses, hazmat, and certain other vehicles must stop every time.
Question 23 of 25
The proper following distance for a 60-foot truck traveling under 40 mph is at least:
  • A 4 seconds
  • B 6 seconds
  • C 10 seconds
  • D 1 second
Correct answer: B
Use one second per 10 feet of vehicle length below 40 mph: 60 ft / 10 = 6 seconds. Add one additional second above 40 mph.
Question 24 of 25
A "wig-wag" is:
  • A A fuel-saving switch
  • B A trailer hitch component
  • C A type of cargo strap
  • D A low-air pressure warning device that drops a flag in front of the driver
Correct answer: D
On older trucks, a wig-wag is a mechanical low-air warning that lowers a flag into the driver's field of view when air pressure drops below safe limits.
Question 25 of 25
Which of the following is a valid reason to refuse a load?
  • A All of the above
  • B It would push your weight over legal limits
  • C The cargo is not properly secured or placarded
  • D It would make you exceed federal hours-of-service rules
Correct answer: A
A driver is required by federal law to refuse loads that violate HOS, weight, or hazmat rules. The driver, not the dispatcher, is liable.

Study tips for the Hawaii General Knowledge exam

The General Knowledge 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 General Knowledge 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 General Knowledge.

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 General Knowledge 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 General Knowledge 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 Air Brakes · HI Combination Vehicles · 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.