Georgia DDS CDL General Knowledge Practice Test 2

Test 2 of 5. Pick an answer for each question to see if it is right and why; your score appears at the end. You need 40 correct answers to pass, the same ratio as the real Georgia test.

A road beneath live oaks with Spanish moss, a typical landscape of Georgia
  1. 1. What is the most common cause of a front-wheel skid, where the vehicle keeps going straight even though you turn the wheel?

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    Answer B: Driving too fast for the conditions

    A front-wheel skid usually comes from too much speed for the traction available; the only cure is to let the vehicle slow down and stop turning or braking so hard.

  2. 2. 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.

  3. 3. How often must every commercial motor vehicle receive a periodic inspection?

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    Answer C: At least once every twelve months

    Federal rules require each commercial motor vehicle to pass a periodic inspection at least once in every twelve month period.

  4. 4. Under the federal air brake standard, the low air pressure warning must come on before reservoir pressure drops below what level?

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    Answer A: Before pressure falls below 60 psi

    Federal Motor Vehicle Safety Standard 121 requires the warning to operate while service reservoir pressure is still above 60 psi, which leaves enough air to bring the vehicle to a normal stop.

  5. 5. 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.

  6. 6. Experienced commercial drivers scan the road ahead by roughly how much travel time?

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    Answer B: About 12 to 15 seconds

    Looking 12 to 15 seconds ahead gives a heavy vehicle enough room to slow or change lanes smoothly instead of reacting late.

  7. 7. An overpass you have driven under before now has a fresh layer of pavement on the road below it. Why does that matter?

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    Answer B: The new layer raises the road and reduces the clearance

    Repaving lifts the road surface, so the real clearance under a structure can be less than the height posted on it.

  8. 8. 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.

  9. 9. A commercial vehicle stops on the shoulder of an undivided two-lane road that carries traffic in both directions. Where do the warning devices go?

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    Answer B: Within 10 feet of the vehicle, plus 100 feet to the front and 100 feet to the rear

    On a two-way road the devices must mark the vehicle itself and warn traffic approaching from each direction, and they must be in place within ten minutes.

  10. 10. A driver is tailgating you, honking and making gestures. What is the best response?

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    Answer A: Do not make eye contact, ignore the gestures and give the driver room to get past

    Engaging an aggressive driver only escalates the situation; the safest move is to stay calm, avoid eye contact and let the driver get by.

  11. 11. 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.

  12. 12. You are hauling livestock and the trailer is only partly full. What should be done?

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    Answer A: Use false bulkheads or partitions to keep the animals bunched together

    Animals that can move around shift the center of gravity, so a partial load is bunched together with partitions to limit how far the weight can move.

  13. 13. You are given a ratchet strap with a deep cut along one edge. What should you do?

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    Answer C: Do not use it; a damaged tiedown cannot be relied on to hold its rated load

    Cuts, burns, knots and broken stitching weaken a strap far below its marked working load limit, so it must be taken out of service.

  14. 14. During the walkaround you notice one tire on an axle is a radial and the tire next to it is bias-ply. What should you do?

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    Answer B: Treat it as a defect, because radial and bias-ply tires must not be mixed on the same axle

    Radial and bias-ply tires flex and grip differently, so mixing them on one axle makes the vehicle handle unpredictably and is not allowed.

  15. 15. 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.

  16. 16. 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.

  17. 17. A strap runs from an anchor point on one side of the trailer, over the load, and down to an anchor point on the opposite side. How much of its working load limit counts toward the total required?

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    Answer C: All of it

    A tiedown that is anchored on one side, passes over or around the cargo and is anchored on the other side counts its full working load limit toward the aggregate figure.

  18. 18. A commercial vehicle stops on the shoulder of a one-way or divided highway. Where do the three warning devices go?

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    Answer A: At 10 feet, 100 feet, and 200 feet back toward approaching traffic

    Traffic arrives from one direction only, so all three devices are set back toward it at 10, 100, and 200 feet, and they must be out within ten minutes.

  19. 19. In Georgia, what does the commercial restriction code K mean on a CDL?

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    Answer B: Intrastate commerce only

    Georgia uses restriction code K for intrastate commerce only, while E covers no manual transmission, L covers no air brakes and O covers no tractor trailer.

  20. 20. What frame defects are you looking for during the walkaround?

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    Answer A: Cracks, bends or broken cross members

    The frame carries the whole load, so cracked or bent rails and broken cross members are serious structural defects.

  21. 21. 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.

  22. 22. You drive a 40 foot straight truck at 50 miles per hour in good conditions. What following distance does the rule of thumb call for?

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    Answer A: 5 seconds

    One second for every 10 feet of vehicle length gives 4 seconds, and one extra second is added for speeds above 40 miles per hour.

  23. 23. When should a lower gear be selected for a long downgrade?

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    Answer D: Before you start down the hill

    The gear is chosen at the top, while speed is still low, because a heavy vehicle already rolling fast may not go into a lower gear at all.

  24. 24. Under federal rules, what happens to a commercial driver found with any detectable amount of alcohol while operating a commercial vehicle?

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    Answer D: The driver is placed out of service for 24 hours

    Any measurable alcohol takes a commercial driver off the road for 24 hours, and a concentration of 0.04 percent or more brings a disqualification.

  25. 25. You are loading a flatbed that has no sides or bulkheads. How must the cargo be held?

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    Answer D: By tiedowns, blocking or bracing, since there are no walls to keep it from shifting or falling off

    Open decks depend entirely on securement devices; every article must be tied down or otherwise immobilized so it cannot move, spill or fall.

  26. 26. Which road users are hardest to see at night?

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    Answer C: Pedestrians and cyclists in dark clothing

    People on foot or on a bicycle carry no lights of their own in many cases, so they appear only when the headlights reach them.

  27. 27. While checking the in-cab gauges after start-up, what should the coolant temperature gauge do?

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    Answer C: Rise gradually to the normal operating range

    A healthy cooling system warms the engine slowly; a gauge that shoots up or stays cold points to a problem with the thermostat, coolant or sensor.

  28. 28. 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.

  29. 29. An angry driver has cut in front of you and is now braking hard to provoke you. What is the safest response?

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    Answer D: Drop back, avoid eye contact and let the driver go

    Giving an aggressive driver space and no response removes the conflict, while any answering gesture invites escalation you cannot control in a heavy vehicle.

  30. 30. 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.

  31. 31. Which set of emergency equipment must be carried on a commercial motor vehicle?

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    Answer D: A fire extinguisher, spare electrical fuses unless the vehicle has circuit breakers, and warning devices

    The required kit is a properly charged and rated fire extinguisher, spare fuses when the vehicle uses them, and warning devices for a stopped vehicle.

  32. 32. Below 40 mph, what following distance does the standard commercial rule of thumb call for?

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    Answer C: One second for every 10 feet of vehicle length

    The base rule allows one second of space for each 10 feet of vehicle length while speed stays under 40 mph.

  33. 33. On the Interstate System, what are the federal maximums for a tandem axle group and for gross vehicle weight?

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    Answer B: 34,000 pounds and 80,000 pounds

    The federal Interstate limits allow 34,000 pounds on a tandem axle group and 80,000 pounds gross.

  34. 34. How is a shipping container normally secured when it is carried on a special container chassis?

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    Answer B: With its own locking devices that attach the container directly to the chassis frame

    Containers built for rail or ship transport have locking corners that fasten to a matching chassis; a container carried on a plain flatbed must be secured like any other cargo.

  35. 35. Your load projects more than 4 feet beyond the rear of the vehicle. How must the projecting end be marked?

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    Answer A: With a red or orange flag by day and a red lamp after dark

    Federal rules require a warning flag on a rear projecting load in daylight and a red lamp on the end of it when lights are required.

  36. 36. Why is cargo often covered with a tarp?

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    Answer C: To protect people from spilled cargo and to protect the cargo from weather

    A cover keeps material from blowing or spilling onto the road and shields the load from rain and sun; it does not replace securement.

  37. 37. How does Georgia charge the CDL road skills test fee?

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    Answer B: $50 for each testing attempt, retained by the department if the applicant does not appear

    Georgia charges the $50 CDL road skills test fee for each testing attempt, and the fee is retained by the department when an applicant fails to appear for the scheduled appointment.

  38. 38. A load overhangs the rear of the trailer. What must the driver check before leaving?

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    Answer D: That the overhang is marked as required, with flags or lamps as conditions demand

    A projecting load has to be made visible to other drivers, with flags in daylight and lamps when lights are required, so nobody runs into what they cannot see.

  39. 39. Why is it harder to judge speed and distance at night?

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    Answer C: You see much less detail and have fewer reference points

    Darkness removes the visual references that the brain uses to estimate distance and closing speed, so drivers routinely misjudge both.

  40. 40. Regular mirror checks during a long trip can reveal which developing problem?

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    Answer D: Smoke coming from a tire or from a wheel

    Overheating tires, wheel bearings and brakes usually show as smoke long before anything appears on the dash, and mirrors are where a driver sees it.

  41. 41. You can see a crack in a brake drum that runs across more than half the width of the friction surface. What does this mean?

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    Answer C: The drum is defective and must be repaired before the vehicle is driven

    Cracks longer than half the width of the friction area mean the drum can break apart under braking heat and must be replaced.

  42. 42. When speed doubles, what happens to braking distance?

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    Answer D: It becomes roughly four times as long

    Braking distance rises with the square of speed, so twice the speed needs about four times the distance to stop.

  43. 43. Why should the mirrors be checked repeatedly while you make a tight turn?

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    Answer C: To watch the rear of the vehicle clear other vehicles and objects

    In a long vehicle the rear wheels cut inside the path of the front wheels, so only the mirrors show whether the rear is clearing curbs, poles and other vehicles.

  44. 44. Which combination of warning devices meets the requirement for a stopped commercial vehicle?

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    Answer A: Three reflective triangles, or six fusees, or three liquid burning flares

    A vehicle may carry three bidirectional reflective triangles, six fusees or three liquid burning flares as its warning devices.

  45. 45. For an unblocked article longer than 10 feet, the minimum is two tiedowns plus how many more?

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    Answer B: One more for every additional 10 feet of length or any part of 10 feet

    Past the first 10 feet, one more tiedown is added for each additional 10 feet of length or any fraction of that distance.

  46. 46. Why should high beams not be used in fog?

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    Answer A: The light reflects back off the droplets and blinds you

    Fog is made of water droplets that scatter light straight back at the driver, so a stronger beam makes the wall of glare worse rather than better.

  47. 47. A chain rated at 6,600 pounds is fitted with a hook rated at 4,700 pounds. What is the working load limit of that assembly?

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    Answer A: 4,700 pounds, the rating of the weakest part

    An assembly is only as strong as its weakest component, so hooks, binders and links all count and the lowest rating governs.

  48. 48. During a trip you stop for a break. Which items should you check before driving on?

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    Answer B: Tires, wheels and rims, brakes, lights, reflectors, electrical connections and cargo securement

    Critical items can change during a trip, so each stop is used to recheck the tires, wheels, brakes, lights, connections and cargo.

  49. 49. Which winter preparation matters most for keeping the road in view?

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    Answer D: Working wipers, washer fluid and a working defroster

    Slush and road spray coat the windshield within minutes in winter, so wipers, washer fluid and the defroster are what keep any view at all.

  50. 50. You are hauling an open box of loose gravel. What does that load require?

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    Answer A: A cover, so that material cannot blow off or spill onto the road

    Loose material that can be blown or spilled has to be covered so it does not come out of the body and strike traffic behind.