Georgia DDS CDL General Knowledge Practice Test 6
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. What does the $35 Georgia CDL application processing fee cover?
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Answer C: Four test attempts
Georgia's $35 CDL application processing fee is good for four test attempts, and it must be renewed if 360 days pass between attempts.
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2. Most rollovers of loaded trucks on exit and entrance ramps happen for which reason?
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Answer B: The ramp was taken faster than the load could tolerate
A posted ramp speed is set for cars, and a loaded trailer with a high center of gravity can roll at a speed a car would take easily.
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3. 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.
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4. 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.
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5. 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.
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6. Under federal safety rules, what must the driver of a commercial vehicle do before starting a trip?
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Answer A: Be satisfied that the vehicle is in safe operating condition
The driver is responsible for inspecting the vehicle and must be satisfied it is in safe operating condition before the trip begins.
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7. Your axle weights are legal, but the tires on that axle are rated below the weight it is carrying. What controls?
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Answer B: The lower figure, so the tires may not be loaded beyond their marked rating
You may never exceed the rating marked on a tire, even when the axle limit would allow more, because an overloaded tire builds heat and can fail.
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8. You pick up a sealed trailer at a shipper. What should you check before leaving the dock?
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Answer B: That the seal number matches the paperwork and that the doors are properly closed
You cannot look at a sealed load, but you can confirm that the seal is intact, that its number matches the documents and that the doors are secure.
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9. A straight truck has a long body behind the rear axle. What happens to that overhang in a sharp left turn?
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Answer D: It swings out to the right and can strike a vehicle or an object on that side
Body that hangs behind the rear axle swings the opposite way to the turn, so the tail of the truck sweeps out into the next lane or over the curb.
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10. 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.
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11. An enforcement officer inspects your vehicle at the roadside and attaches an out-of-service sticker. What may you do?
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Answer C: Nothing until the defect is repaired; the vehicle may not be driven
An out-of-service order means the vehicle is unsafe, and no schedule, load or destination allows it to be driven before the defect is corrected.
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12. Besides the hours when the law requires them, when should headlights be switched on?
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Answer A: Any time visibility is poor, such as in rain, fog or at dusk
Headlights are used to be seen as much as to see, so they belong on whenever light or weather makes the vehicle harder to spot.
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13. The car in the next lane still has snow covering most of its windows. What should you assume?
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Answer C: That driver cannot see you and may move into your lane
A driver whose view is blocked cannot see the vehicles around, so you should assume you are invisible and stay out of that vehicle path.
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14. Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?
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Answer C: After 8 cumulative hours of driving time
Driving is not allowed after 8 cumulative hours of driving time without at least a 30 consecutive minute interruption of driving.
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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. 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.
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17. 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.
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18. What is the correct way to test the parking brake before a trip?
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Answer C: With the parking brake set, put the vehicle in a low gear and gently try to move forward
A parking brake that holds against a gentle pull in low gear is working; if the vehicle moves, the brake needs adjustment or repair.
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19. How does the working load limit of a tiedown relate to the force that would break it?
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Answer B: The working load limit is a fraction of the breaking strength and is the figure you use
The working load limit is set well below the point at which the device would fail, and securement is always calculated from the working load limit, never from breaking strength.
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20. 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.
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21. During the walkaround you find the reflective conspicuity tape along the trailer caked with road grime. What should you do?
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Answer B: Clean it, because dirty reflective material cannot make the trailer visible at night
Reflective sheeting only works if light can reach it and bounce back, so a dirty strip leaves the trailer effectively unmarked to approaching traffic.
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22. 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.
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23. 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.
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24. How should the headlamps be checked during the pre-trip inspection?
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Answer A: By switching on both low beam and high beam and confirming each one works outside
Both beams are separate circuits, so each is switched on in turn and confirmed from outside the vehicle where the lamps can actually be seen.
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25. How long may a Georgia commercial learner's permit be held?
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Answer C: No more than 365 days
Georgia limits the commercial learner's permit to one year, or 365 days, before it can no longer be held.
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26. 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.
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27. What is wrong with resting your foot on the clutch pedal between shifts?
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Answer B: It slowly wears the clutch out, because the pressure plate is never fully engaged
Any weight on the pedal partly disengages the clutch, so it slips and wears; the foot belongs off the pedal once the shift is finished.
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28. You are pulling away from a curb in a 65 foot combination. Besides traffic, what must you watch?
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Answer B: The trailer wheels, which stay close to the curb and can strike it or an object on it
Because of off-tracking, the rear wheels follow a tighter path than the front, so they stay near the curb while the cab is already out in the lane.
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29. How does a load carried high in the trailer affect safe speed through a curve?
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Answer B: It raises the rollover risk, so the speed must be lower
A high center of gravity lets the vehicle tip long before the tires lose their grip, so height of the load directly limits curve speed.
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30. How are the headlights, marker lights and turn signals checked during the seven-step inspection?
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Answer A: The engine is shut off, the parking brake is set, the lights are switched on and then checked from outside the vehicle
The lights are switched on with the vehicle secured, then the driver walks around and confirms each lamp actually works and is clean.
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31. 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.
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32. 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.
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33. On a wet road, a commercial driver should reduce speed by roughly how much?
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Answer C: By about one third
Cutting speed by roughly a third, for example from 55 to about 35 mph, restores a margin for the traction lost on a wet surface.
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34. In a vehicle with a manual transmission, when should the clutch be pushed in during a normal stop?
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Answer A: Just before the engine would stall, when the vehicle is nearly stopped
Staying in gear until the last moment keeps engine braking and steady control, so the clutch goes down only when the engine is about to drop below idle.
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35. On a two lane road carrying traffic in both directions, where do the three warning devices go?
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Answer C: About 10 feet from the vehicle on the traffic side, 100 feet behind and 100 feet ahead
Traffic can approach from either direction, so one device goes close to the vehicle and one is placed about 100 feet away in each direction.
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36. 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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37. An intermodal container is being carried on an ordinary flatbed rather than on a container chassis. What does that mean for securement?
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Answer B: It must be secured with tiedowns that meet the container securement requirements
A container carried on a vehicle that is not fitted with integral locking devices has to be secured to the deck with tiedowns that satisfy the rules for containers.
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38. Which factors determine a safe speed for a long, steep downgrade?
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Answer C: The steepness and length of the grade, the weight of the vehicle and cargo, and the road and weather conditions
Gravity, weight and traction all decide how fast a heavy vehicle can safely descend, which is why signs often post lower speeds for trucks on grades.
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39. Why does a load of live animals need special attention?
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Answer D: The animals move and lean, so the center of gravity shifts and the vehicle can be pushed off balance in a turn
A live load will not stay where it is put, and that movement changes the balance of the vehicle exactly when a curve is loading it most.
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40. 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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41. What are you checking when you pull the engine oil dipstick during the pre-trip?
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Answer A: That the oil level is within the safe operating range marked on the stick
The dipstick shows whether there is enough oil to lubricate and cool the engine, and a level outside the safe range must be corrected before driving.
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42. 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.
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43. 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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44. 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.
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45. What is the minimum tread depth required in every major groove of a steering axle tire?
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Answer D: 4/32 inch
Federal rules set a higher tread minimum for front steering tires than for other positions because a steering tire failure is far harder to control.
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46. 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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47. 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.
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48. When turning left, what should a driver of a long vehicle do before beginning the turn?
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Answer B: Reach the center of the intersection so the rear wheels clear the corner
The rear wheels follow a tighter path than the front, so the vehicle must reach the center of the intersection before the turn begins.
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49. A brake light lens is cracked and the lamp still lights. How should that be treated?
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Answer B: As a defect, because water can enter and the lamp can dim or fail
A cracked lens lets in water and dirt, which corrodes the socket and dulls the lamp, so it is reported before it becomes a dead brake light.
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50. An empty van trailer cleared a low overpass on the way in, but on the way back it is loaded. Which statement is true?
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Answer C: An empty van rides higher than a loaded one, so it needs more clearance than when loaded
Springs compress under load, so an empty trailer is taller; the unloaded trip is the one that can catch a low overhead.