Alabama ALEA CDL General Knowledge Practice Test 9

  • Questions50
  • Correct to pass40
  • Passing score80%
  • Minimum age18 years

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

  1. 1. A tire may be regrooved only when what is true?

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    Answer B: It carries a marking from the manufacturer showing that it is regroovable

    Only casings built with extra rubber under the tread and marked regroovable by the manufacturer may be cut, because others would be grooved into the belts.

  2. 2. You want to check whether a tire on your truck is properly inflated. What is the correct method?

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    Answer A: Measure the pressure with a tire gauge

    Only a tire gauge tells you the actual pressure; a tire can look and sound normal while being badly underinflated.

  3. 3. Which windshield condition should be reported during the inspection?

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    Answer B: Cracks or dirt that get in the way of your view of the road

    The windshield must give a clear view; damage or grime in the driver line of sight is a safety defect.

  4. 4. Within what distance should high beams be lowered at night?

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    Answer D: Within about 500 feet of an oncoming vehicle and within about 500 feet of a vehicle you are following

    High beams blind other drivers at close range, so they are lowered at roughly the same distance whether the other vehicle is coming toward you or is ahead of you.

  5. 5. Where must a vehicle that is required to stop at an Alabama railroad grade crossing come to a halt?

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    Answer B: Within 50 feet but not less than 15 feet from the nearest rail

    Alabama requires the driver of a vehicle covered by the rule to stop within 50 feet but not less than 15 feet from the nearest rail before crossing.

  6. 6. 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.

  7. 7. When a helper guides you while backing, what should be agreed on before you start?

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    Answer D: A set of hand signals, especially the signal that means stop

    The driver and helper must agree on signals in advance, above all the stop signal, because they usually cannot hear each other.

  8. 8. Besides obtaining a commercial learner permit, what must a first time Alabama CDL applicant complete before the commercial driver license is issued?

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    Answer D: Entry Level Driver Training

    ALEA requires first time CDL applicants to complete Entry Level Driver Training in addition to holding the commercial learner permit.

  9. 9. 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.

  10. 10. Where is the yellow antilock brake malfunction lamp on a trailer, and what does it mean if it stays lit?

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    Answer D: On the left side, at the front or rear corner, and it means the antilock function may not be working

    Trailers carry the yellow lamp on the left side, and a lamp that stays on after the bulb check means the antilock function may be lost even though the normal brakes still work.

  11. 11. What does a front-end header board on a van or flatbed protect against?

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    Answer A: Cargo moving forward toward the cab in a crash or hard stop

    The header board, often called a headache rack, blocks forward movement of the load toward the driver.

  12. 12. Does the federal texting ban apply to a company dispatching device mounted in the cab?

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    Answer B: Yes, entering or reading text on it while driving is banned

    The rule is written around the act of reading or entering text on any electronic device, not around who owns the device.

  13. 13. On a multilane highway, which lane should a heavy vehicle normally use?

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    Answer A: The right lane, except to pass or where signs direct otherwise

    Keeping right leaves the faster lanes free and reduces the number of vehicles that have to move around a slower, heavier vehicle.

  14. 14. 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.

  15. 15. Which set of maneuvers makes up the basic control skills part of the commercial driving test?

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    Answer D: Straight line backing, offset backing, parallel parking and alley docking

    The basic control skills test is carried out off the road and consists of low speed exercises such as straight line backing, offset backing, parallel parking and the alley dock.

  16. 16. Why must a bent, cracked or badly seated lock ring be reported?

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    Answer D: It can come off under pressure and let the tire and rim separate violently

    The lock ring holds the assembly together against the full pressure of the tire, so a damaged ring can release with enough force to kill.

  17. 17. Your truck has a backup alarm that sounds whenever reverse is selected. What may a driver rely on it for?

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    Answer D: Very little; it warns some people but cannot show you what is behind the vehicle

    An alarm may not be heard over yard noise or by someone wearing hearing protection, so it never replaces looking at the path yourself.

  18. 18. Why must the downshift be finished before you reach a steep downgrade or a sharp curve rather than during it?

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    Answer D: Because once your speed is too high you may not get into any gear at all

    If you wait until speed has built up, the lower gear may refuse to engage and you can be left in neutral with no engine braking at all.

  19. 19. What happens to braking performance if oil or grease reaches a brake lining?

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    Answer B: That brake loses much of its effect and the vehicle can pull to one side

    A contaminated lining cannot grip the drum, so that wheel contributes little braking and the vehicle pulls toward the side that is still working.

  20. 20. How should a commercial driver treat the speed posted for a curve?

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    Answer B: As a limit set for cars in good conditions, so a heavy or tall load calls for a lower speed

    Posted curve speeds are based on passenger vehicles in good conditions, and a tall or heavy load can roll over well below that speed.

  21. 21. You normally pull an empty trailer, but today the same tractor is loaded to its legal maximum. What changes about getting under way?

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    Answer A: You may need to start in a lower gear, since the load takes more pulling power

    The heavier the load, the lower the gear needed to get the vehicle rolling without lugging or stalling the engine.

  22. 22. 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.

  23. 23. You are unsure whether your vehicle will fit through a narrow gate. What should you do?

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    Answer A: Stop, get out and look, and take another route if the space is not clearly enough

    Clearance is never guessed at from the seat; you look at it on foot and go round rather than trying a gap that may be too tight.

  24. 24. What does the tachometer on the dashboard of a heavy truck show?

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    Answer D: How fast the engine is turning, in revolutions per minute

    The tachometer reads engine speed in rpm, which is what a driver uses to judge shift points in a vehicle with a manual transmission.

  25. 25. A sign before a long descent shows 6 percent. What does that number tell you?

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    Answer A: How steep the grade ahead is

    Percent grade is the drop in feet for every hundred feet of road, so the higher the number the faster speed will build and the lower the gear you need.

  26. 26. At the scale your tractor drive axles are overweight while the trailer axles have room. Sliding the trailer tandems forward will do what?

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    Answer C: Move weight off the drive axles and onto the trailer axles

    Sliding the trailer tandems forward brings the rear support closer to the load, so the trailer axles pick up more weight and the drive axles carry less; sliding them rearward does the opposite.

  27. 27. 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.

  28. 28. While double clutching, what goes wrong if you take too long between the two clutch movements?

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    Answer A: Engine speed falls too far and the gear becomes hard or impossible to engage

    Double clutching only works while engine speed and road speed still match; a slow shift lets rpm drop away and the gear will not go in.

  29. 29. Some commodities have their own detailed securement rules on top of the general ones. Which list is made up of such commodities?

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    Answer C: Logs, metal coils, paper rolls, concrete pipe and crushed vehicles

    The cargo securement rules add specific requirements for particular commodities, including logs, dressed lumber, metal coils, paper rolls, concrete pipe, intermodal containers, vehicles, crushed cars, roll on containers and large boulders.

  30. 30. What happens to braking distance when speed is doubled?

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    Answer C: It becomes about four times longer

    Braking distance grows with the square of speed, so doubling the speed multiplies both the braking distance and the force of an impact by about four.

  31. 31. Cargo carried inside the cab must never do which of these?

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    Answer C: Block the driver view, restrict arm or leg movement, or block an emergency exit

    Anything inside the cab must leave the driver a clear view, free movement of the arms and legs, and an unobstructed way out of the vehicle.

  32. 32. What is generally the safest speed in dense but freely moving highway traffic?

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    Answer D: The speed of the traffic around you, up to the posted limit

    Crashes rise with the difference between your speed and the traffic around you, so moving with the flow within the legal limit is safest.

  33. 33. 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.

  34. 34. Why is braking while in a curve dangerous in a heavy vehicle?

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    Answer A: The wheels lock more easily and the vehicle can skid

    Tires already using their grip to turn have little left for braking, so hard braking in a curve locks the wheels; slow down before the curve instead.

  35. 35. What are you checking on the mud flaps during the walkaround?

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    Answer C: That they are securely attached, not torn and not dragging on the ground

    A flap that is torn or hanging loose stops shielding following traffic from spray and stones, and a dragging flap can catch and tear away on the road.

  36. 36. You drop your phone on the floor of the cab while driving. What do federal rules require?

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    Answer A: Leave it, because reaching for it while driving is banned

    Federal rules forbid reaching for a mobile device in any way that takes the driver out of a seated, belted driving position.

  37. 37. What actually lowers the amount of alcohol in the bloodstream?

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    Answer B: Time

    The liver removes alcohol at a fixed rate, so nothing but the passage of time reduces blood alcohol concentration.

  38. 38. 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.

  39. 39. 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.

  40. 40. How does a driver keep a vehicle with a manual transmission from rolling back when starting on an upgrade?

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    Answer D: Partly engage the clutch before the right foot leaves the brake, or hold the vehicle with the parking brake until the engine pulls

    Something has to hold the vehicle during the instant the foot moves from the brake to the accelerator, and that is either the clutch at its engagement point or the parking brake.

  41. 41. What extinguisher rating is required on a vehicle carrying hazardous materials in amounts that need placards?

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    Answer B: 10 B:C or more

    Placarded loads carry a much higher fire risk, so the required extinguisher rating rises to at least 10 B:C.

  42. 42. What is the main purpose of a retarder fitted to a heavy vehicle?

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    Answer B: To help slow the vehicle and reduce the need to use the service brakes

    Exhaust, engine, hydraulic and electric retarders all slow the vehicle so the brakes stay cool and wear less, especially on grades.

  43. 43. What is the purpose of blocking placed against cargo on a trailer deck?

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    Answer B: To fill the space around the cargo so it cannot slide

    Blocking is shaped to fit snugly against the cargo and fastened to the deck, removing the room the load would need in order to move.

  44. 44. You have just passed another vehicle on a two lane road. What tells you it is safe to return to your lane?

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    Answer B: You can see the whole front of that vehicle in your right mirror

    Seeing the entire front of the vehicle you passed in your mirror proves you are far enough ahead to move back over without cutting the driver off.

  45. 45. What blood alcohol concentration disqualifies the holder of a commercial driver license who is operating a commercial vehicle?

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    Answer D: 0.04 or higher

    Commercial drivers are held to 0.04, half the limit that applies to a driver of a passenger car in the same state.

  46. 46. What are you looking for when you check the hubs and wheel seals during the walkaround?

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    Answer B: Leaking oil or grease, which can also contaminate the brake linings

    A leaking hub seal starves the bearing of lubricant and the escaping oil or grease can soak the brake linings and cut braking power.

  47. 47. After two hours of driving you measure a tire and the pressure reads higher than the cold figure. What should you do?

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    Answer B: Nothing, because pressure rises normally as a tire heats up in use

    Air expands as the tire heats, so a higher hot reading is expected, and letting air out leaves the tire underinflated once it cools.

  48. 48. Before raising the hood to inspect the engine compartment, what should you do?

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    Answer B: Shut off the engine, set the parking brake and chock the wheels if needed

    The engine compartment is inspected with the engine off and the vehicle secured so nothing can move or turn while your hands are inside.

  49. 49. A doctor prescribes you a medicine that can cause drowsiness. What should you do?

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    Answer A: Tell the doctor what you drive and not drive while affected

    Both prescription and over the counter medicines can make a driver unsafe, so the medical professional must know the job and the driver must stay out of the seat while affected.

  50. 50. How does bracing differ from blocking when securing cargo?

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    Answer B: Bracing runs from the upper part of the cargo to the floor or walls to keep it from moving, while blocking fits snugly against the cargo

    Blocking is shaped to fit against the front, back or sides of a piece of cargo; bracing supports it from above so it cannot tip or shift.