Georgia DDS CDL General Knowledge Practice Test 5
Test 5 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.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. Under the federal hours of service rules, how long may a property-carrying driver drive after 10 consecutive hours off duty?
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Answer D: Up to 11 hours, and only within a 14 hour window that starts when the driver comes on duty
The federal limit is 11 hours of driving after 10 consecutive hours off duty, and all of that driving has to fall inside a 14 hour window.
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2. Compared with a fully loaded one, an empty truck under hard braking will often do what?
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Answer A: Need a longer distance to stop because traction is poor
Stiff suspension and little weight over the tires reduce grip, so the wheels lock early and the vehicle can take longer to stop.
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3. What must be checked on a sliding fifth wheel during the inspection?
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Answer B: That it is locked in position and not so far forward that the trailer can hit the cab
A slider that is unlocked can move under braking, and one set too far forward lets the trailer strike the cab when the tractor turns sharply.
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4. Federal rules keep recapped and retreaded tires off the front wheels of which vehicle?
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Answer B: Any bus carrying passengers
The federal rule names buses: a bus may not run with regrooved, recapped or retreaded tires on its front wheels, because a steer tire failure with passengers aboard takes away steering control.
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5. Your brakes have failed and you decide to use the parking brake to slow down. Why should you hold the release button or lever while doing so?
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Answer D: So you can release the brake at once if the wheels lock and the vehicle starts to skid
The parking brake can lock the wheels; keeping your hand on the release lets you let go the moment a skid starts and regain control.
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6. What must the driver confirm about the required emergency equipment before a trip?
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Answer A: That it is in place, in working order and ready to be used
Federal rules require the driver to be satisfied that the emergency equipment is present and ready, because it is needed at the worst possible moment.
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7. At 55 mph on dry pavement with good brakes, total stopping distance for a loaded heavy vehicle is roughly what?
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Answer B: About 400 feet or more
Perception, reaction, and braking together add up to roughly 400 feet or more, farther than the length of a football field.
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8. Why is a leak in the exhaust system especially dangerous in cold weather?
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Answer A: Carbon monoxide can build up inside a closed cab
In winter the windows are shut and the heater is running, so exhaust gas that escapes early can reach the driver and cause drowsiness or worse.
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9. What must the driver check about the seat belt during the inspection?
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Answer A: That it is securely mounted, adjusts properly and is not ripped or frayed
A belt only restrains the driver if its anchorage is sound and the webbing is intact, so mounting and condition are both checked.
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10. Why do cracked spring hangers or badly worn shackles matter?
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Answer A: They allow the axle to shift out of its correct position under the vehicle
Hangers and shackles hold the spring, and therefore the axle, in place, so when they fail the axle can move and the vehicle may become uncontrollable.
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11. During the walkaround you notice a bulge in the sidewall of a trailer tire. What does it indicate?
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Answer B: Damage inside the tire, which can lead to a sudden failure
A bulge means the internal structure has broken and only the rubber is holding the air, so the tire can burst without warning.
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12. Which exhaust system condition must be reported as a defect?
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Answer B: A section repaired by wrapping tape or patching material around the pipe
Exhaust parts may not be patched with wrap or tape, because the repair does not contain the gas or the heat and it fails quickly in service.
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13. 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.
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14. Why is driving much slower than the rest of the traffic dangerous?
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Answer B: Other drivers must keep passing you, which creates conflicts
Traffic that has to work its way around you produces lane changes and closing speeds, which is why a large speed difference is itself a hazard.
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15. Cargo securement must be strong enough to hold the load under which conditions?
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Answer A: Hard braking, hard acceleration and hard turning, as well as the bouncing of the road
The securement standard is written around the forces of a hard stop, a hard start, a hard turn and vertical movement on a rough surface, all of which occur in ordinary driving.
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16. Besides being uncomfortable, what can a series of hard, jerky brake applications do to a loaded combination?
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Answer A: Shift the load and push the trailer out of line behind the tractor
Sudden, uneven braking can move cargo forward and upset the alignment of a trailer, which is why stops should be made smoothly.
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17. 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.
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18. A fire starts in the cargo area of a van trailer. Why should you keep the doors closed until firefighters arrive?
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Answer D: Opening the doors lets in air that feeds the fire
A fire in a closed van is starved of oxygen; opening the doors gives it the air it needs to flare up.
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19. What is checked in step six of the seven-step method?
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Answer D: The turn signals and the stop lights, checked from outside the vehicle
Step six returns to the cab to switch on the signal and stop lamps, then checks each one from outside, because those lamps are not lit during the earlier light check.
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20. 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.
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21. What should you look for on the electrical wiring in the engine compartment?
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Answer A: Worn, frayed or cracked insulation and loose or corroded connections
Damaged insulation can short a circuit against the frame or engine, which can kill a lamp you depend on or start a fire.
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22. What does Georgia require of a commercial vehicle when winter weather closes in on a limited access road?
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Answer C: Tire chains, four-wheel drive with adequate tires, or snow tires with an all weather rating
Georgia requires vehicles in winter conditions to have tire chains, four-wheel drive with tires adequate for the conditions, or snow tires carrying a manufacturer's all weather rating.
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23. You have chosen 40 miles per hour as your safe speed for a downgrade. How should the brakes be used?
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Answer A: Brake firmly to about 35, release, and repeat at 40
Proper technique is firm application to about 5 miles per hour below the safe speed, then full release so the brakes cool before the next application.
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24. Which document must be available to show that the annual inspection was carried out?
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Answer C: The inspection report or a copy of it, or a decal displayed on the vehicle
Proof of the periodic inspection travels with the vehicle, either as the report itself or as the decal fixed where an inspector can see it.
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25. What is normally required in order to move an over-width or over-length load?
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Answer B: A special permit along with warning devices such as flags and signs
Oversize movements need a permit plus marking devices, and travel is often limited to certain hours or routes.
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26. Why should a driver avoid stopping partway up a snow covered hill?
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Answer D: You may not get moving again and could slide backwards
On a slippery grade the drive wheels may simply spin when you try to restart, leaving the vehicle stuck across the road or sliding back down it.
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27. Where on a tire is tread depth measured?
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Answer C: In a major tread groove, away from any tie bar or wear indicator
Depth is taken in a major groove and away from the raised tie bars and wear indicators, which would give a shallower and misleading reading.
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28. At a stop on a hot day you find a tire that is too hot to touch. What should you do?
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Answer C: Wait until the tire cools before driving on, and do not let air out of it
A tire that is too hot to touch may be about to fail or catch fire; releasing air only leaves it underinflated once it cools, which makes things worse.
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29. 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.
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30. Besides staying secure, cargo carried inside a vehicle must not do what?
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Answer C: Block the driver view or access to emergency equipment and exits
Cargo may not obstruct the view to the front or sides or prevent the driver from reaching emergency equipment and exits.
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31. Why are the windshield wipers on the pre-trip list even before a trip in fine weather?
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Answer C: Because weather can change and a wiper failure leaves the driver without a clear view
Rain, spray or mud can arrive at any point in a long trip, and a wiper that fails then leaves the driver with no way to clear the windshield.
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32. A tire blows out at highway speed. What should the driver do first?
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Answer C: Hold the steering wheel firmly, stay off the brake and let the vehicle slow down
Braking while a tire is gone can pull the vehicle out of line, so the driver keeps it straight and lets speed fall before easing off the road.
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33. You are about to cross a long, high bridge with a light load in gusty wind. What should you do?
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Answer C: Slow down and be ready for a sudden push
Wind is strongest where a bridge leaves the shelter of the land, and lower speed gives you time to correct when the first gust hits.
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34. Under federal rules, which commercial vehicles must stop at every railroad crossing before proceeding?
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Answer D: Passenger buses and placarded hazardous materials vehicles
Buses carrying passengers and vehicles required to display hazardous materials placards must stop at crossings, while other commercial vehicles slow and check.
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35. Where do you find the maximum weight a tire can safely carry?
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Answer D: Stamped on the sidewall of the tire itself
Each tire is marked with the greatest weight it can carry at a stated inflation pressure, and the load on an axle must stay within the total for its tires.
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36. Why should you never shift gears while crossing railroad tracks?
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Answer A: You could miss the gear or stall and be stuck on the tracks
A stalled or coasting vehicle on the tracks has no way to clear quickly, so choose the gear before the crossing and do not shift until you are across.
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37. With water standing on the road, hydroplaning can begin at speeds as low as what?
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Answer D: 30 mph
When enough water covers the surface, the tires can ride up on it and lose contact at speeds as low as 30 mph.
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38. Apart from the legal duty, what is the main practical reason for a thorough pre-trip inspection?
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Answer A: It finds problems that could cause a breakdown or a crash before the vehicle is on the road
A defect found in the yard is an inconvenience, while the same defect found at highway speed can be a crash, so the inspection is where problems are cheapest to fix.
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39. What does the commercial driver manual tell you to do with the parking brake when you leave your vehicle?
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Answer B: Apply the parking brake every time you leave the vehicle
The manual is explicit that the parking brake goes on whenever the driver leaves the vehicle, because once nobody is at the controls it is the only thing holding it.
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40. At what time of day do drowsy driving crashes occur most often?
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Answer A: Between midnight and 6 a.m.
The body clock makes people sleepiest in the early morning hours, which is when most fatigue-related crashes happen.
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41. 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.
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42. You have countersteered to correct a rear-wheel skid and the vehicle straightens out. What must you be ready for next?
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Answer D: The vehicle may swing back the other way, so you must steer again to correct it
A vehicle coming out of a skid tends to overshoot and swing in the opposite direction, and the driver must be ready to countersteer a second time.
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43. 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.
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44. You pick up a trailer that another driver dropped in the yard. What must you do before pulling it?
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Answer B: Inspect it yourself, because you are responsible for the whole vehicle you drive
Responsibility follows the driver who moves the vehicle, and a trailer that has stood in a yard may have lost air, developed a flat tire or been damaged.
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45. What must the motor carrier do about a defect listed on a driver vehicle inspection report?
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Answer D: Repair it, or certify that repair is not needed, before the vehicle is dispatched again
A reported defect must be corrected, or certified as not needing correction, and that certification is what the next driver reads before taking the vehicle.
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46. What should be done before a night trip to get the most from your headlights?
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Answer C: Clean the windshield, the mirrors and the lights
Dirt on glass and lenses cuts both the light you throw down the road and the light that reaches your eyes, so cleaning is the cheapest night safety measure there is.
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47. What must a written driver vehicle inspection report cover at the end of the day?
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Answer C: Any defect or deficiency that would affect safety or could cause a mechanical breakdown
The report identifies the vehicle and lists defects that affect safe operation or could lead to a breakdown, so they are repaired before the next trip.
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48. You have stopped and a pedestrian is waiting to cross in front of your truck. Why should you not wave the person across?
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Answer C: Another driver may not stop, and your wave sends the person into danger
You cannot control what drivers in the other lanes will do, so you should not invite a pedestrian into a lane you do not command.
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49. 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.
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50. During the engine compartment check, which leaks are you looking for?
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Answer D: Fuel, coolant, engine oil, power steering fluid and battery fluid
Every fluid in the compartment matters, because a fuel leak is a fire risk and a loss of coolant, oil, steering fluid or electrolyte can disable the vehicle.