Illinois SOS CDL General Knowledge Practice Test 6
- Questions30
- Correct to pass24
- Passing score80%
- Minimum age18 years
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1. 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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2. During the vehicle overview, what should the driver look for on the ground under the vehicle?
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Answer B: Fresh puddles of oil, coolant, grease or fuel
New stains on the ground are the earliest sign of a leak, so the overview includes a look underneath before anything is opened or started.
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3. 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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4. You need to pull off onto the shoulder because of a problem with the load. How should you communicate that to other drivers?
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Answer D: Signal the move, then switch on the four-way flashers once stopped
Other drivers need a signal before you leave the lane and a clear warning once the vehicle is stopped near the traffic lanes.
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5. 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.
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6. Besides allowing the move at all, what does an oversize load permit usually set out?
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Answer C: The route to be followed, the hours of travel allowed and the warning equipment needed
Permits for oversize movements normally name the roads that may be used, restrict the times of travel, and list the flags, signs and escorts required.
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7. 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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8. A dispatcher tells you to take a trailer you believe is loaded badly enough to be unsafe. What should you do?
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Answer C: Refuse to move it until the load has been made safe
The driver may not operate a vehicle whose cargo is not properly distributed and secured, and an instruction from an employer does not change that.
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9. 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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10. On a scale, your loaded truck is well under the gross weight limit, but one axle is above the limit for that axle. What does this mean?
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Answer D: The vehicle is overloaded and the load must be shifted or reduced before you drive on
Each axle and axle group has its own limit and each must be respected; being under the gross limit does not excuse an overloaded axle.
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11. What is the correct order for a basic double clutch upshift?
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Answer B: Release the accelerator and push the clutch, shift to neutral, release the clutch, let engine speed drop, push the clutch again and shift to the higher gear
Double clutching passes through neutral with the clutch released so engine speed can drop to match the next gear before it is engaged.
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12. During a right turn in a tractor-trailer, what are you looking for in the right hand mirror?
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Answer B: Whether the trailer will clear the curb and whether anything has moved alongside you
The right mirror is what tells you how close the trailer wheels are running to the curb and whether a vehicle or a cyclist has slipped into the space on your right.
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13. 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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14. 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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15. 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.
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16. Your vehicle stalls on a railroad crossing and a train is coming. What should you do?
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Answer C: Get out at once and move toward the train, well off to one side
Leave the vehicle immediately and move at an angle toward the oncoming train, so that wreckage thrown forward by the impact travels away from you.
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17. 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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18. A carrier operates commercial vehicles every day of the week. What weekly on-duty limit applies to its drivers?
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Answer A: 70 hours in 8 consecutive days
The limit is 60 hours in 7 consecutive days for a carrier that does not run every day, and 70 hours in 8 consecutive days for one that does.
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19. What should you check about the tire valve stems during the walkaround?
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Answer D: That the stems are not cut, cracked or leaking and the caps are in place
A split stem or a missing cap lets air escape or lets dirt into the valve, and either one can flatten a tire between stops.
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20. 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.
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21. 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.
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22. Besides slowing down, which technique most reduces the risk of a skid on a snow covered road?
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Answer B: Make every steering, braking and speed change gradual
Traction is limited on snow, and sudden inputs demand more grip than the surface can supply, so smoothness is what keeps the tires attached to the road.
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23. 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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24. Which vehicle is most likely to be pushed around by a strong crosswind?
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Answer B: An empty van trailer
A large flat side with very little weight behind it gives the wind the most surface and the least resistance, which is the empty van trailer.
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25. 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.
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26. A driver hauling a sealed trailer that cannot be opened is still responsible for what?
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Answer D: Making sure the rig is not over the gross or axle weight limits
A seal prevents inspecting the contents, but the driver must still confirm the vehicle is not overloaded.
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27. You are backing a tractor-trailer in a straight line and the trailer starts to drift to the left. What is the standard correction?
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Answer D: Turn the top of the steering wheel a little to the left, toward the drift
Small corrections made in the direction the trailer is drifting bring it back into line; large or opposite movements make the drift worse.
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28. Why should a driver avoid shifting gears in the middle of a turn at an intersection?
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Answer D: Shifting during the turn takes a hand off the wheel and can cost you control
Pick the gear before you begin turning; shifting in the turn removes a hand from the wheel and can interrupt power just when you need steady control.
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29. Why should a retarder be switched off when the road is wet, icy or snowy?
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Answer C: It can make the drive wheels skid when traction is poor
A retarder slows the drive wheels only, and on a slippery surface that braking force can break their traction and start a skid.
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30. Which description matches controlled braking during an emergency stop?
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Answer D: Apply the brakes as hard as you can without locking the wheels and keep steering movements small
Controlled braking keeps the wheels rolling just short of lockup, which gives the shortest stop while you keep the ability to steer.