Illinois SOS CDL General Knowledge Practice Test 11

  • Questions30
  • Correct to pass24
  • Passing score80%
  • Minimum age18 years

Minimum age: 18 years for an intrastate CLP or CDL; 21 years for interstate operation or to transport passengers

30 questions. Pick an answer to see if it is right and why; you need 24 correct answers to pass.

  1. 1. On a one way street or a divided highway, where are the warning devices placed?

    Show answer

    Answer B: About 10 feet, 100 feet and 200 feet back toward the approaching traffic

    When traffic can only come from one side, all three devices are spread out behind the vehicle to give approaching drivers a longer warning.

  2. 2. Part of looking well ahead is planning an out. What does that mean?

    Show answer

    Answer B: Keeping an escape path in mind in case traffic stops suddenly

    Because a heavy vehicle often cannot stop in time, good drivers continuously note where they could steer if the space ahead closes.

  3. 3. Why is backing toward the driver side preferred?

    Show answer

    Answer C: You can watch the rear of the vehicle directly through the side window

    Backing to the left lets the driver look out the window and see the rear of the vehicle directly instead of relying on a mirror alone.

  4. 4. You are backing into a yard where electrical wires cross overhead. What is the main concern?

    Show answer

    Answer C: The wires may hang lower than the top of your vehicle

    Overhead space has to be checked like any other space around the vehicle, because wires and cables are often lower than they look from the cab.

  5. 5. Which of these is NOT on the federal list of parts and accessories the driver must be satisfied are in good working order before driving?

    Show answer

    Answer D: The seat cushion upholstery

    The federal pre-trip rule names brakes, steering, lights and reflectors, tires, horn, wipers, mirrors, coupling devices, wheels and rims, and emergency equipment; seat upholstery is not on that list.

  6. 6. What should you look for on the electrical wiring in the engine compartment?

    Show answer

    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.

  7. 7. Which clues warn you that a parked car may pull out or open a door?

    Show answer

    Answer A: Exhaust smoke, turned front wheels, a person in the seat

    Signs of life in a parked vehicle, such as a running engine, turned wheels or an occupant, mean it may move or open a door into your path.

  8. 8. A dock crew loads all of the freight at the very back of a 48 foot van trailer. What are the two consequences?

    Show answer

    Answer A: The steering axle is relieved of weight and steering becomes light, and the trailer axles may go over the limit

    Weight placed far to the rear lifts weight off the front of the combination, so the steering goes light while the trailer axles take too much of the load.

  9. 9. After two hours of driving you measure a tire and the pressure reads higher than the cold figure. What should you do?

    Show answer

    Answer B: Nothing, because pressure rises normally as a tire heats up in use

    Air expands as the tire heats, so a higher hot reading is expected, and letting air out leaves the tire underinflated once it cools.

  10. 10. At 55 mph on dry pavement with good brakes, total stopping distance for a loaded heavy vehicle is roughly what?

    Show answer

    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.

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

    Show answer

    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.

  12. 12. Your speedometer stops working during the pre-trip check. How should it be treated?

    Show answer

    Answer D: As a defect, because the driver cannot judge and control speed without it

    A working speedometer is required equipment, because judging speed by feel in a heavy vehicle is unreliable and speed governs stopping distance.

  13. 13. How long must the record of a periodic inspection be kept?

    Show answer

    Answer A: Fourteen months

    The periodic inspection report is retained for fourteen months from the date of the report, which covers the full twelve month cycle plus a margin.

  14. 14. You are about to slow down sharply on a highway to make a turn into a narrow driveway. How can you warn the drivers behind you?

    Show answer

    Answer C: Tap the brake pedal a few times so the brake lights flash before you slow down

    A few light taps flash the brake lights and give following drivers an early warning that you are about to slow or stop.

  15. 15. Why should you never back under a trailer whose landing gear is resting on soft or muddy ground?

    Show answer

    Answer C: The landing gear can sink or collapse and the trailer can drop or tip over

    Soft ground lets the landing gear sink under the load being transferred to it, and a trailer that drops or topples during coupling is extremely dangerous.

  16. 16. You press on a drive belt and it deflects far more than the others. What does that suggest?

    Show answer

    Answer C: The belt is too loose and the part it drives may not work properly

    A belt with excessive play slips on its pulleys, so the accessory it drives turns too slowly or not at all under load.

  17. 17. Rust streaks are running outward from the lug nuts on one wheel. What does this most likely indicate?

    Show answer

    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.

  18. 18. Why do cracked spring hangers or badly worn shackles matter?

    Show answer

    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.

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

    Show answer

    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.

  20. 20. What does a front-end header board on a van or flatbed protect against?

    Show answer

    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.

  21. 21. Taking your eyes off the road for about five seconds at highway speed means traveling roughly how far unseen?

    Show answer

    Answer A: About the length of a football field

    At highway speed a five second glance away covers roughly 100 yards, which is far more road than any driver can afford to travel blind.

  22. 22. Cargo carried inside the cab must never do which of these?

    Show answer

    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.

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

    Show answer

    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.

  24. 24. Why must tiedowns be rechecked during a trip even when they were tight at the start?

    Show answer

    Answer C: Road vibration and cargo movement can loosen them as the miles go by

    Straps and chains settle and loosen as the vehicle bounces and the cargo shifts slightly, so the load must be rechecked at the required intervals.

  25. 25. Compared with a fully loaded one, an empty truck under hard braking will often do what?

    Show answer

    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.

  26. 26. You pick up a trailer that another driver dropped in the yard. What must you do before pulling it?

    Show answer

    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.

  27. 27. Why should a driver avoid traveling alongside another vehicle for any length of time?

    Show answer

    Answer D: You lose your escape route and you may be sitting in the other driver blind spot

    Running beside someone leaves nowhere to move if you have to change lanes, and the other driver may not know you are there at all.

  28. 28. Why does the manual insist on a firm grip with both hands on opposite sides of the steering wheel?

    Show answer

    Answer A: A hard bump can pull the wheel out of a loose grip

    Hitting a curb or a deep pothole can jerk the wheel violently, and only a firm two-handed grip keeps the vehicle under control when that happens.

  29. 29. Your truck has a backup alarm that sounds whenever reverse is selected. What may a driver rely on it for?

    Show answer

    Answer D: Very little; it warns some people but cannot show you what is behind the vehicle

    An alarm may not be heard over yard noise or by someone wearing hearing protection, so it never replaces looking at the path yourself.

  30. 30. A doctor prescribes you a medicine that can cause drowsiness. What should you do?

    Show answer

    Answer A: Tell the doctor what you drive and not drive while affected

    Both prescription and over the counter medicines can make a driver unsafe, so the medical professional must know the job and the driver must stay out of the seat while affected.