Hawaii HDOT MVSO CDL General Knowledge Practice Test 7

  • Questions50
  • Correct to pass40
  • Passing score80%
  • Minimum age21 years

50 questions. Pick an answer to see if it is right and why; you need 40 correct answers to pass.

  1. 1. Why should the radio, the fan and other noisy equipment be switched off during a required stop at a railroad crossing?

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    Answer C: So that an approaching train can be heard

    The rules require the driver to look and listen along the track, and on a double track crossing a passing train can hide a second one, so hearing matters as much as seeing.

  2. 2. A driver snores heavily, stops breathing briefly during the night and is tired all day despite long hours in bed. What should be suspected?

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    Answer B: Sleep apnea

    Sleep apnea repeatedly interrupts breathing during sleep, so the driver never gets true rest and stays dangerously drowsy during the day.

  3. 3. Why does a driver use pull-ups while backing into a tight space?

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    Answer C: To pull forward and start the approach again when the angle is going wrong

    Stopping, pulling ahead and repositioning fixes a bad angle safely, and there is nothing wrong with needing more than one attempt.

  4. 4. An article of cargo has been blocked so that it cannot move forward. How many tiedowns does the federal rule call for?

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    Answer A: One tiedown for every 10 feet of article length, or any part of that

    Blocking against forward movement lowers the requirement to one tiedown per 10 feet of length or fraction of 10 feet.

  5. 5. Where are the OVERSIZE LOAD signs normally carried on a vehicle moving under such a permit?

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    Answer A: On the front and the rear of the vehicle

    The warning signs face the traffic that meets the load and the traffic that comes up behind it, so they go on the front and the rear.

  6. 6. What does the driver check in the final step of the seven-step inspection?

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    Answer A: Hydraulic brake leaks where those brakes are fitted, then the parking brake and the service brakes

    The last step is done with the engine started: test for hydraulic leaks on vehicles with hydraulic brakes, then prove that the parking brake holds and that the service brakes stop the vehicle.

  7. 7. What does it mean to overdrive your headlights at night?

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    Answer D: Driving so fast that you cannot stop within the distance lit by your headlights

    You must be able to stop inside the distance you can see; at night that distance is limited by the headlights, so speed must be lowered to match.

  8. 8. You find one lug nut missing from a wheel that has ten studs. What should you do?

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    Answer C: Treat it as a defect and have it repaired before the vehicle is driven

    Every missing fastener loads the others more heavily, and wheel separations usually begin with one nut that nobody replaced.

  9. 9. You are about to slow down sharply on a highway to make a turn into a narrow driveway. How can you warn the drivers behind you?

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    Answer C: Tap the brake pedal a few times so the brake lights flash before you slow down

    A few light taps flash the brake lights and give following drivers an early warning that you are about to slow or stop.

  10. 10. When is a road surface usually most slippery during a rain shower?

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    Answer A: Just after the rain starts, when water mixes with oil and dirt on the surface

    The first rain lifts oil and dust into a slick film that has not yet been washed away, so the road is more slippery than it will be later.

  11. 11. What is the driver looking for when the exhaust system is inspected?

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    Answer B: Loose, broken or missing pipes, brackets or clamps, and signs that exhaust is leaking

    A loose or leaking exhaust system can send carbon monoxide into the cab and can put hot gas against parts that will burn.

  12. 12. What should a driver assume about the height posted at a bridge or an overpass?

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    Answer B: That it may be wrong, because repaving or packed snow can leave less clearance than the sign shows

    Resurfacing and packed snow raise the road under the structure, so the real clearance can be lower than the posted figure.

  13. 13. Where are regrooved, recapped or retreaded tires not allowed on a truck or truck tractor?

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    Answer C: On the front steering wheels

    Regrooved and retreaded tires are prohibited on the front wheels of a truck or truck tractor because a steering tire blowout is extremely difficult to manage.

  14. 14. How much sleep does a typical adult driver need each day to stay properly alert?

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    Answer D: Seven to eight hours

    Most adults need seven to eight hours of sleep in every 24 hours, and a driver who regularly gets less builds up a debt that shows up behind the wheel.

  15. 15. How much free play in the steering wheel is enough to make a vehicle hard to steer and should be reported?

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    Answer B: More than 10 degrees, roughly 2 inches of movement at the rim of a 20 inch wheel

    Excess play means steering input is lost before the wheels respond, and more than about 10 degrees is treated as a defect.

  16. 16. Why do worn tires lose grip so quickly on a wet road?

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    Answer D: Shallow tread cannot move water out from under the tire

    The grooves in a tire exist to channel water away so the rubber can touch the road, and a worn tire has lost that capacity.

  17. 17. A commercial driver is convicted of two serious traffic violations within three years. What is the result?

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    Answer D: Disqualification for 60 days

    Two serious traffic violations in a three year period bring a 60 day disqualification, and a third in the same period raises it to 120 days.

  18. 18. What is the purpose of the torque rods or radius rods you check on the suspension?

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    Answer A: They hold the axle in alignment with the frame under braking and acceleration

    Torque rods resist the twisting and fore and aft forces on the axle, so a cracked or missing rod lets the axle move out of alignment.

  19. 19. During a right turn in a tractor-trailer, what are you looking for in the right hand mirror?

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    Answer B: Whether the trailer will clear the curb and whether anything has moved alongside you

    The right mirror is what tells you how close the trailer wheels are running to the curb and whether a vehicle or a cyclist has slipped into the space on your right.

  20. 20. A vehicle becomes unsafe while you are already on the road. What does the federal rule allow?

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    Answer A: Continuing only to the nearest place where repairs can safely be made

    If stopping where you are would be more dangerous than moving, the rule allows you to reach the nearest place where the vehicle can safely be repaired, and no further.

  21. 21. A driver behind you wants to pass and you can see that the road ahead is clear. What should you do?

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    Answer B: Do not signal the other driver to pass; let that driver decide when it is safe

    Directing other drivers can cause a crash if you misjudge the gap, so leave the decision to the driver who is passing.

  22. 22. On a set of dual tires, which condition must be reported as a defect?

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    Answer D: The two tires are touching each other or rubbing on part of the vehicle

    Duals that touch each other or the vehicle overheat and wear quickly, so they must be separated by proper spacing and inflation before driving.

  23. 23. You are hauling a sealed trailer and have been told in writing not to open it. How does that affect the en route cargo checks?

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    Answer C: You do not have to inspect the cargo itself, but the vehicle and weight are still yours

    The en route cargo inspection rule does not apply to a driver of a sealed vehicle who has been ordered not to open it, but every other responsibility, including legal weight, remains.

  24. 24. What information does an inspection decal on a commercial vehicle carry?

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    Answer B: The date of the inspection, where the inspection report is kept, and information identifying the vehicle

    The decal shows when the inspection was done, the name and address of the entity that holds the inspection report, and which vehicle it belongs to, so an officer can confirm the inspection at a glance.

  25. 25. Using the snub braking method on a downgrade, when does the driver release the brakes?

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    Answer A: After speed has dropped about 5 mph below the safe speed

    The driver brakes firmly to about 5 mph under the chosen safe speed, releases to let the brakes cool, then repeats when the safe speed returns.

  26. 26. You must leave the vehicle parked on a slight grade. What adds security beyond setting the parking brake?

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    Answer D: Chocking the wheels so the vehicle cannot roll if the brake bleeds off

    Chocks hold the vehicle mechanically and are the standard backup whenever a parked vehicle could roll.

  27. 27. What does the working load limit stamped on a chain or strap describe?

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    Answer B: The maximum load the device is rated to hold in normal use

    The working load limit is the rated safe capacity for everyday use, deliberately set well below the force that would break the device.

  28. 28. Where is a dunnage bag used and how does it work?

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    Answer D: Between pieces of cargo inside a van, where it is inflated to take up the gap

    A dunnage bag is placed in the void between loads and inflated so the cargo is wedged and cannot move as the vehicle rolls and brakes.

  29. 29. When should the horn of a commercial vehicle be used?

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    Answer C: Only when it is needed to avoid a crash

    An air horn is loud enough to startle other road users, so it is a warning device rather than a way to comment on other drivers.

  30. 30. You are about to back across a quiet street into a driveway. Which of these is good practice before you start to move?

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    Answer B: Turn on the four-way flashers and sound the horn to alert anyone nearby

    Warning other road users and pedestrians before a reverse maneuver gives them the chance to stop or move clear before the vehicle starts back.

  31. 31. Part of your load stands high enough to hide a rear lamp or a reflector. What must be done?

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    Answer B: The load must be moved or extra lamps fitted so the required lights can be seen

    Required lamps and reflectors must remain visible; if the cargo blocks them, the load is rearranged or additional lamps are fitted so the vehicle can still be seen.

  32. 32. At 55 mph, about how far does a vehicle travel during a typical 3/4 second perception time plus 3/4 second reaction time, before the brakes even begin to work?

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    Answer C: About 120 feet

    Each 3/4 second at 55 mph covers about 60 feet, so perception and reaction together use up roughly 120 feet before braking starts.

  33. 33. Dry bulk tanks call for extra caution mainly because of what?

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    Answer C: A high center of gravity combined with a load that can shift

    Dry bulk loads ride high and can move inside the tank, which makes the vehicle easier to tip in a curve.

  34. 34. Federal rules forbid operating a commercial vehicle in which condition?

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    Answer C: In a condition likely to cause a crash or a breakdown

    A defect that makes a crash or a breakdown likely has to be corrected before the vehicle is driven, not reported at the end of the trip.

  35. 35. You are moving an oversized load under a permit that requires a pilot vehicle. What is the pilot vehicle there to do?

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    Answer B: Warn other traffic and check the route ahead for clearances and hazards

    Escort or pilot vehicles warn approaching traffic and scout the route for low bridges, narrow spots and other hazards that a wide or long load cannot pass.

  36. 36. The brake pedal goes to the floor in a vehicle with hydraulic brakes. What can you do to build some braking pressure?

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    Answer B: Pump the brake pedal rapidly, which may bring back enough pressure to slow the vehicle

    Pumping can restore some hydraulic pressure; along with downshifting and the parking brake it is one of the ways to stop when the pedal fails.

  37. 37. You must steer hard around an obstacle at highway speed. What is the correct technique?

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    Answer B: Avoid braking while turning, turn only as far as needed, and countersteer as soon as the obstacle is passed

    Braking during a hard steering input can lock the wheels and start a skid, and turning back at once keeps the vehicle from running off the far side of the road.

  38. 38. During a stop you find a package in the trailer leaking an unknown chemical. What should you do?

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    Answer C: Keep clear, keep others away and get help without touching the package

    A driver without the training and equipment does not handle a leak; the job is to protect people from the material and get qualified help to the scene.

  39. 39. Your brakes have failed on a downgrade and there is no escape ramp in sight. What is the best choice?

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    Answer A: Steer into an open field or onto a side road that flattens out or climbs uphill

    A flat or uphill escape route uses gravity and rolling resistance to stop the vehicle; take it as soon as you see it, because the longer you wait the faster you go.

  40. 40. When is tire pressure most accurately compared with the recommended figure?

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    Answer B: When the tires are cold, before the vehicle has been driven

    Recommended pressures are cold pressures, so a reading taken before the tires have heated up is the only one that can be compared directly.

  41. 41. What are the rules for using your turn signal before a turn or lane change?

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    Answer A: Signal early, keep the signal on until the turn is finished, then cancel it

    An early, continuous signal tells others what you plan to do; cancelling afterward keeps the signal from misleading them.

  42. 42. A carrier operates commercial vehicles every day of the week. What weekly on-duty limit applies to its drivers?

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    Answer A: 70 hours in 8 consecutive days

    The limit is 60 hours in 7 consecutive days for a carrier that does not run every day, and 70 hours in 8 consecutive days for one that does.

  43. 43. What happens if a Hawaii CDL stays expired for more than one year?

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    Answer D: The driver must start over and take the written test as well as the road test

    Hawaii allows 90 days after expiry to renew, then charges $5 per month, and after a full year past expiry the applicant must begin again with the written and road tests.

  44. 44. On a tractor with a sliding fifth wheel, what does moving the fifth wheel forward do?

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    Answer A: Puts more of the trailer weight onto the steering axle

    Moving the coupling point forward transfers weight from the drive axles to the steering axle, which is how a driver corrects a drive axle that is over the limit.

  45. 45. You are stopped in a line of traffic behind a car. How much space should you leave in front of you?

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    Answer C: Enough to see where the rear tires of that car meet the road

    That amount of space lets you pull around the vehicle ahead if it stalls and absorbs some of the shock if you are struck from behind.

  46. 46. What is the correct order for a double clutch downshift?

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    Answer D: Release the accelerator and push the clutch to reach neutral, release the clutch and press the accelerator to raise engine speed, then push the clutch again and select the lower gear

    A lower gear turns faster than the one being left, so engine speed has to be raised in neutral before that gear will engage cleanly.

  47. 47. Why should water never be used on an electrical fire or a gasoline fire?

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    Answer C: It spreads the fuel and conducts the current

    Water carries current back to the person holding the hose and floats burning fuel outward, which is why a B:C rated extinguisher is carried instead.

  48. 48. Why should a long vehicle never swing out to the left before starting a right turn?

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    Answer D: Another driver may read it as a left turn or pass on your right

    Swinging left opens a gap on your right that a car will move into, and it also sends a false message about which way you are going.

  49. 49. What speed and gear should be used when backing a large vehicle?

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    Answer B: As slowly as possible, in the lowest reverse gear

    Backing slowly in the lowest reverse gear keeps the vehicle under precise control and leaves time to correct the path.

  50. 50. Why is a quick lane change particularly risky with a load of hanging meat or of livestock?

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    Answer A: The load swings or leans and can keep pushing the trailer after you straighten out

    A swinging or leaning load keeps moving after the vehicle has finished the maneuver, so its momentum acts on the trailer at the worst moment.