Kentucky KYTC CDL General Knowledge Practice Test 8
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. What is the best practice when fog is thick enough to hide the road ahead?
Show answer
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.
-
2. Why do worn tires lose grip so quickly on a wet road?
Show answer
Answer D: Shallow tread cannot move water out from under the tire
The grooves in a tire exist to channel water away so the rubber can touch the road, and a worn tire has lost that capacity.
-
3. During the vehicle overview, what should the driver look for on the ground under the vehicle?
Show answer
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.
-
4. What blood alcohol concentration disqualifies the holder of a commercial driver license who is operating a commercial vehicle?
Show answer
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.
-
5. When is tire pressure most accurately compared with the recommended figure?
Show answer
Answer B: When the tires are cold, before the vehicle has been driven
Recommended pressures are cold pressures, so a reading taken before the tires have heated up is the only one that can be compared directly.
-
6. A carrier operates commercial vehicles every day of the week. What weekly on-duty limit applies to its drivers?
Show answer
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.
-
7. Which lights should be used in fog, by day or by night?
Show answer
Answer A: Low beams and fog lights, together with the four-way flashers
High beam light bounces back off the water droplets and makes seeing worse, while low beams, fog lights and flashers help you see and help others see you.
-
8. An unblocked article is 15 feet long. What is the minimum number of tiedowns?
Show answer
Answer B: Three
Two tiedowns cover the first 10 feet and one more is added for each further 10 feet or any part of it, so 15 feet needs three.
-
9. What do the U-bolts on a leaf spring suspension do?
Show answer
Answer A: They clamp the spring assembly to the axle so it cannot move
U-bolts hold the spring pack tight against the axle, and a loose or broken U-bolt lets the axle slide out of place under load.
-
10. In very hot weather, how often should you check the tires during a trip?
Show answer
Answer D: About every two hours or every 100 miles
Heat raises tire pressure and can lead to blowouts, so tires are checked about every two hours or 100 miles when it is very hot.
-
11. When a helper guides you while backing, what should be agreed on before you start?
Show answer
Answer D: A set of hand signals, especially the signal that means stop
The driver and helper must agree on signals in advance, above all the stop signal, because they usually cannot hear each other.
-
12. You are moving an oversized load under a permit that requires a pilot vehicle. What is the pilot vehicle there to do?
Show answer
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.
-
13. What is checked in step six of the seven-step method?
Show answer
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.
-
14. Why is braking while in a curve dangerous in a heavy vehicle?
Show answer
Answer A: The wheels lock more easily and the vehicle can skid
Tires already using their grip to turn have little left for braking, so hard braking in a curve locks the wheels; slow down before the curve instead.
-
15. Which lamp must make the rear registration plate legible after dark?
Show answer
Answer C: A white lamp that lights the plate
A white license plate lamp is required so the plate can be read at night, and a burned out one is a defect like any other lamp.
-
16. During uncoupling, when may the fifth wheel locking lever be released?
Show answer
Answer D: Only after the landing gear is down and taking the weight of the trailer
The landing gear has to be supporting the trailer before the lock is released; otherwise the trailer nose can drop as soon as the tractor pulls out.
-
17. Where should a trailer be dropped, and what else does the driver do before pulling out from under it?
Show answer
Answer C: On solid level ground, with the trailer wheels chocked if it may roll
A dropped trailer must sit on ground that will carry the landing gear without sinking, and chocks stop it rolling once the tractor and its air supply are gone.
-
18. What should you check about the tire valve stems during the walkaround?
Show answer
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.
-
19. What does safe practice require of a commercial driver who wants to eat, drink or read a delivery note?
Show answer
Answer B: Handle it before or after driving, not while moving
Anything that takes hands, eyes or attention away from the task belongs outside the driving time, not inside it.
-
20. During the walkaround you find the reflective conspicuity tape along the trailer caked with road grime. What should you do?
Show answer
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.
-
21. Which winter preparation matters most for keeping the road in view?
Show answer
Answer D: Working wipers, washer fluid and a working defroster
Slush and road spray coat the windshield within minutes in winter, so wipers, washer fluid and the defroster are what keep any view at all.
-
22. 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.
-
23. 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?
Show answer
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.
-
24. How do you confirm that the coupling is locked before pulling out of the yard?
Show answer
Answer D: By locking the trailer brakes and pulling gently forward against them
The tug test loads the coupling in the direction that would pull it apart, so if the jaws are not closed on the kingpin you find out at walking pace.
-
25. Which brake lining condition must be reported?
Show answer
Answer C: Linings that are worn thin, loose, cracked or soaked with oil or grease
Linings must have enough material left and must be securely attached and clean, because a thin, loose or contaminated lining cannot deliver its share of braking.
-
26. What are you looking for when you check the drive belts in the engine compartment?
Show answer
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.
-
27. A hard frost has left your vehicle covered in ice. What must be cleared before you drive?
Show answer
Answer D: The windshield, mirrors, lights and reflectors
You must be able to see out and other drivers must be able to see your lights and reflectors, so all of those surfaces have to be cleared.
-
28. How is a shipping container normally secured when it is carried on a special container chassis?
Show answer
Answer B: With its own locking devices that attach the container directly to the chassis frame
Containers built for rail or ship transport have locking corners that fasten to a matching chassis; a container carried on a plain flatbed must be secured like any other cargo.
-
29. The shipper hands you the placards for a load that needs them. Who puts them on the vehicle?
Show answer
Answer C: The driver, who must also make sure they are the correct ones and are readable
The shipper supplies the placards, but it is the driver who must place them on the vehicle and confirm that they match the load and can be read.
-
30. Your right wheels drop off the pavement onto a soft shoulder. What is the correct recovery?
Show answer
Answer A: Stay on the shoulder, ease off the accelerator, brake gently only once speed is down to about 20 mph, then steer back sharply and countersteer at once
Bringing speed down on the shoulder first avoids a violent sideways jolt, and countersteering the instant the tires are back on the pavement keeps the vehicle out of the next lane.
-
31. Why does a driver use pull-ups while backing into a tight space?
Show answer
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.
-
32. Your drive wheels start to spin and the rear begins to slide while you accelerate on a slick surface. What should you do?
Show answer
Answer B: Stop accelerating and, if the vehicle has a manual transmission, push in the clutch
An acceleration skid ends when the drive wheels stop pushing, so easing off the throttle and disengaging the clutch lets them regain grip.
-
33. 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.
-
34. Which of these counts as a serious traffic violation for a commercial driver license holder?
Show answer
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.
-
35. Within what distance should high beams be lowered at night?
Show answer
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.
-
36. 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.
-
37. 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?
Show answer
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.
-
38. As a long vehicle goes around a corner, how do the rear wheels travel compared with the front wheels?
Show answer
Answer A: They follow a tighter path, closer to the inside of the turn
The rear wheels off-track toward the inside of the turn, and the longer the vehicle the bigger the difference, which is why the front must swing wide enough to keep the rear off the curb.
-
39. You are making a right turn and cannot complete it without swinging into the oncoming lane. An oncoming car is approaching. What should you do?
Show answer
Answer A: Wait and let the oncoming vehicle pass before completing the turn, and do not back up
The oncoming vehicle has the lane; backing up in traffic is dangerous, so hold your position and finish the turn once the way is clear.
-
40. What does the gross combination weight rating cover?
Show answer
Answer B: The maximum loaded weight of the power unit together with the trailer or trailers it tows
The combination rating takes in the power unit and everything behind it, loaded, as specified by the manufacturer.
-
41. What does Kentucky require of a CDL applicant who has already failed the skills test four times?
Show answer
Answer D: A seven-day wait before the fifth attempt, on top of the retest fee
Kentucky charges a retest fee for each attempt after the first, and after four attempts the applicant must wait seven days before the fifth.
-
42. When speed doubles, what happens to braking distance?
Show answer
Answer D: It becomes roughly four times as long
Braking distance rises with the square of speed, so twice the speed needs about four times the distance to stop.
-
43. How does bracing differ from blocking when securing cargo?
Show answer
Answer B: Bracing runs from the upper part of the cargo to the floor or walls to keep it from moving, while blocking fits snugly against the cargo
Blocking is shaped to fit against the front, back or sides of a piece of cargo; bracing supports it from above so it cannot tip or shift.
-
44. When should mirror adjustment be checked, and what should each mirror show?
Show answer
Answer B: Before every trip, with each mirror adjusted to show some part of the vehicle
Checking the mirrors before each trip and keeping a small part of the vehicle in view gives a reference point for judging distance behind and beside you.
-
45. Your axle weights are legal, but the tires on that axle are rated below the weight it is carrying. What controls?
Show answer
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.
-
46. Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?
Show answer
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.
-
47. What is generally the safest speed in dense but freely moving highway traffic?
Show answer
Answer D: The speed of the traffic around you, up to the posted limit
Crashes rise with the difference between your speed and the traffic around you, so moving with the flow within the legal limit is safest.
-
48. You drop your phone on the floor of the cab while driving. What do federal rules require?
Show answer
Answer A: Leave it, because reaching for it while driving is banned
Federal rules forbid reaching for a mobile device in any way that takes the driver out of a seated, belted driving position.
-
49. What is the danger of letting engine speed climb past the top of the rated rpm range before you shift?
Show answer
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.
-
50. How do you test for leaks in a hydraulic brake system during the pre-trip inspection?
Show answer
Answer A: Pump the pedal three times, then hold firm pressure for five seconds and make sure the pedal does not move
If the pedal sinks while you hold pressure, fluid is escaping or air is in the lines, and the vehicle must not be driven until the problem is repaired.