Georgia DDS CDL General Knowledge Practice Test 10
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. How does a typical escape ramp stop a runaway vehicle?
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Answer B: With a bed of loose gravel or sand, often on an upgrade
Escape ramps use deep loose material, usually combined with a rising grade, so the vehicle is slowed gradually instead of being stopped by impact.
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2. You hear air escaping from a trailer tire during the pre-trip. What should you do?
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Answer C: Have it repaired or replaced before the vehicle is driven
An audible leak means the tire is failing now, and federal rules do not allow a vehicle to be operated on a flat or leaking tire.
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3. Before starting a trip, what must the driver confirm about the weight of the loaded vehicle?
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Answer A: That it is within the legal gross and axle limits for the route being driven
Overweight vehicles brake poorly, damage tires and suspension components, and can be put out of service at a scale, so weight is checked before the wheels turn.
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4. 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.
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5. What are you looking for when you check the drive belts in the engine compartment?
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Answer C: That each belt is snug and free of cracks, frays or heavy wear
A loose or cracked belt can break and stop the fan, the water pump or the alternator, which leads quickly to overheating or a dead electrical system.
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6. You need fuel and the canopy over the pumps is low. What is the safe way to handle the clearance?
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Answer B: Stop and check the height at the entrance and at the way out before committing
Clearance can differ at the entry, under the canopy and at the exit, and a sloping approach changes the effective height, so both ends have to be checked.
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7. 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.
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8. What is the risk when too little weight rests on the drive axles?
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Answer A: Poor traction, so the drive wheels spin easily on wet or slippery surfaces
Traction depends on weight pressing the driving tires onto the road, so a light drive axle spins on wet, snowy or loose surfaces.
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9. What should you do with the previous driver vehicle inspection report before starting your trip?
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Answer B: Review it and confirm that listed defects were certified as repaired or as not needing repair
Reviewing the last report and the carrier certification tells you whether reported defects have been corrected before you take the vehicle out.
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10. How are the extra gears of a multi-speed rear axle or auxiliary transmission usually controlled?
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Answer D: With a selector knob or switch on the gearshift lever of the main transmission
A range selector on the shift lever lets the driver choose the extra gear range while shifting the main transmission.
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11. 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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12. What is checked about the engine cooling system during the engine compartment inspection?
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Answer C: That the coolant level is adequate and the radiator and hoses are not leaking
A low coolant level or a leaking hose leads to overheating, which can stop the vehicle in a place where stopping is dangerous.
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13. 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.
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14. 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.
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15. 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.
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16. You are strapping down a load with sharp metal edges on a flatbed. What should you use?
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Answer D: Edge protection between the strap and the sharp edges so the tiedown is not cut
Sharp edges cut or wear through a strap under tension, so edge protectors are required wherever a tiedown could be damaged.
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17. Rust streaks are running outward from the lug nuts on one wheel. What does this most likely indicate?
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Answer C: The lug nuts may be loose
Rust trails spreading from the nuts are a classic sign that the nuts have worked loose and the wheel has been moving on the studs.
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18. 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.
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19. What are you looking for on the brake drums during the walkaround?
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Answer B: Cracks, dents and any oil or grease that has reached the friction surface
A cracked or badly scored drum can break apart under braking heat, and oil or grease on the friction surface destroys the braking effort at that wheel.
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20. 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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21. 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.
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22. What is the best practice when fog is thick enough to hide the road ahead?
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Answer B: Slow down before entering the fog, and if visibility is too poor, pull off into a rest area or truck stop until it improves
The safest choice in heavy fog is not to be driving in it, and if you are already in it your speed has to come down before your visibility does.
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23. How soon must warning devices be placed after a commercial vehicle stops on the traveled part or the shoulder of a highway?
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Answer D: As soon as possible and in any case within 10 minutes
The hazard warning flashers go on immediately and the warning devices must be in place as soon as possible, never later than 10 minutes after stopping.
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24. 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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25. 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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26. The combined working load limit of the tiedowns on a load must equal at least what share of the cargo weight?
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Answer C: One half of the cargo weight
Federal securement rules set the aggregate working load limit at no less than half the weight of the article or group of articles being held.
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27. 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.
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28. 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.
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29. 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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30. What is the danger of letting engine speed climb past the top of the rated rpm range before you shift?
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Answer B: You can damage the engine, so the shift should be made before that point
Every engine has a rated operating range; running above it can cause serious engine damage, so the upshift belongs at the top of that range, not beyond it.
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31. You are dropping a loaded trailer in a yard. How far should the landing gear be lowered?
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Answer A: Until the pads make firm contact and the trailer weight is just off the fifth wheel
Cranking down until the gear is firmly on the ground and just lifting the load off the fifth wheel makes the trailer stable and lets the tractor pull out cleanly.
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32. How should the steering wheel be held when driving a large vehicle?
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Answer D: Firmly with both hands, placed on opposite sides of the wheel
Both hands on opposite sides give the leverage and control needed if a tire drops off the pavement or the wheel is jolted.
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33. Which of these counts as a serious traffic violation for a commercial driver license holder?
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Answer C: Speeding 15 miles per hour or more above the limit
Excessive speeding, reckless driving, improper lane changes, following too closely and texting while driving are all serious traffic violations.
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34. How is the fluid level in an automatic transmission usually checked?
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Answer A: With the engine running, following the procedure in the operator manual
Most automatic transmissions are designed to be checked with the engine running, and the operator manual gives the exact conditions for that vehicle.
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35. 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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36. What should be checked about the power steering system in the engine compartment?
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Answer D: That the fluid level is correct and the hoses and pump are not leaking
Losing power steering fluid means losing steering assistance, which can happen suddenly and makes a heavy vehicle very hard to turn.
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37. 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.
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38. 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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39. 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.
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40. Which step of the seven-step inspection method comes immediately after checking the engine compartment?
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Answer D: Start the engine and inspect the inside of the cab
Once the hood is closed the driver moves to the driver seat, starts the engine and checks gauges, controls and warning devices before going any further.
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41. What color must the clearance and side marker lamps and reflectors at the front of a trailer be?
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Answer A: Amber
Amber marks the front and the forward part of the sides of a vehicle, while red marks the rear, so another driver can tell which way the vehicle is facing.
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42. What is the driver responsible for when a load is covered with a tarp?
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Answer C: Fastening it so it cannot flap free, block a mirror, or come off in the wind
A tarp that works loose can tear away, block the driver view or the view of others, and become a hazard for the traffic behind.
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43. When traction is poor, such as on packed snow, how should you speed up?
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Answer C: Very gradually, so the drive wheels do not spin
Gentle throttle keeps the drive wheels from breaking traction, because spinning wheels give up both grip and directional control.
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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.
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45. 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.
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46. 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.
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47. What do you check about the fire extinguisher during the pre-trip?
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Answer C: That it is securely mounted, charged and that you know how to operate it
An extinguisher must be held in its bracket, show a charged gauge and be understood by the driver, because a fire leaves no time to learn.
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48. Why must you never coast down a hill in neutral or with the clutch pushed in?
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Answer C: You lose the braking effect of the engine and your brakes may overheat and fail
Engine braking is what keeps a heavy vehicle in check on a grade; coasting throws it away and leaves the service brakes to do all the work until they overheat.
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49. 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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50. 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.