Wyoming WYDOT CDL General Knowledge Practice Test 1
Test 1 of 5. Pick an answer for each question to see if it is right and why; your score appears at the end. You need 40 correct answers to pass, the same ratio as the real Wyoming test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. 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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2. On a multilane highway, which lane should a heavy vehicle normally use?
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Answer A: The right lane, except to pass or where signs direct otherwise
Keeping right leaves the faster lanes free and reduces the number of vehicles that have to move around a slower, heavier vehicle.
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3. Why should a driver avoid traveling alongside another vehicle for any length of time?
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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.
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4. 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?
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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.
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5. 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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6. 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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7. Two tires in a dual set have noticeably different diameters. Why is that a problem?
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Answer C: The larger tire carries more than its share of the load and can be overloaded
The taller tire touches the road first and takes most of the weight, so it runs overloaded and hot while the smaller one does little work.
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8. Which parts of total stopping distance can a driver shorten simply by staying alert and looking far ahead?
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Answer B: Perception distance and reaction distance
Alertness shortens the time spent recognizing a hazard and moving your foot to the pedal; braking distance depends on speed, weight, brakes and the road surface.
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9. What does safe practice require of a commercial driver who wants to eat, drink or read a delivery note?
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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.
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10. Why can an empty truck need a longer stopping distance than a loaded one?
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Answer C: An empty vehicle has less traction, so its wheels lock up more easily
Brakes and tires are designed for a loaded vehicle, and with little weight on the axles the tires grip less and lock sooner.
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11. 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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12. When must a driver first inspect the cargo and its securement devices?
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Answer C: Before starting the trip, as part of the pre-trip inspection
Cargo is part of the pre-trip inspection; the later checks within 50 miles and every three hours or 150 miles come on top of that first inspection.
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13. What does the federal bridge formula do?
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Answer C: It reduces the weight allowed on a group of axles as those axles get closer together
Axles bunched together concentrate the load on a short span of a bridge, so the formula lowers the allowable weight as the spacing shrinks.
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14. 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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15. Which steering system findings count as defects during the inspection?
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Answer C: Bent, loose or broken column parts, arms, drag links or tie rods, and missing nuts, bolts or cotter keys
Every joint and fastener between the steering wheel and the tires carries the driver commands, so looseness or a missing retainer can end in a complete loss of steering.
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16. 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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17. 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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18. 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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19. How long is a Wyoming commercial learner permit valid, and how long must it be held before the skills test?
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Answer D: Valid 365 days and held at least 14 days before skills testing
A Wyoming commercial learner permit is valid for 365 days and must be held for at least 14 days before the applicant may take the skills test.
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20. A company mechanic serviced your truck this morning and signed the work order. Do you still have to inspect the vehicle?
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Answer B: Yes, the driver is still responsible for being satisfied the vehicle is safe
Shop work does not transfer the duty; the driver who takes the vehicle out remains responsible for being satisfied it is in safe operating condition.
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21. 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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22. During the walkaround you notice a bulge in the sidewall of a trailer tire. What does it indicate?
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Answer B: Damage inside the tire, which can lead to a sudden failure
A bulge means the internal structure has broken and only the rubber is holding the air, so the tire can burst without warning.
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23. 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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24. Which clues warn you that a parked car may pull out or open a door?
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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.
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25. What is the most common cause of a front-wheel skid, where the vehicle keeps going straight even though you turn the wheel?
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Answer B: Driving too fast for the conditions
A front-wheel skid usually comes from too much speed for the traction available; the only cure is to let the vehicle slow down and stop turning or braking so hard.
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26. A hazard suddenly appears ahead and you must act. Which is usually the faster way to avoid it in a heavy vehicle?
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Answer B: Steering around it, because you can usually turn faster than you can stop
Stopping distance at speed is very long, so a quick turn out of the way, when there is room, avoids the crash sooner than braking.
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27. In hazard perception, what counts as a hazard?
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Answer C: Any road user or condition that could become a danger
A hazard is anything with the potential to create danger, which is why drivers are taught to spot them early rather than react to emergencies.
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28. Why must the steering wheel be moved only a small amount at a time while backing?
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Answer B: Because a small turn of the wheel produces a large change at the rear of the vehicle
In reverse, the effect of the steering is greatly magnified at the back of the vehicle, so a small correction is usually all that is needed.
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29. Which brake lining condition must be reported?
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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.
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30. You are on a freeway and see brake lights come on in several vehicles far ahead of you. What should you do?
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Answer A: Ease off the accelerator and get ready to slow down
Brake lights well ahead are an early warning that traffic is slowing, and acting on them gives a heavy vehicle the room it needs.
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31. What must be true of the person who performs the annual periodic inspection?
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Answer D: They must meet the federal qualification requirements for an inspector
The inspection has to be done by someone who meets the federal training and experience requirements for inspectors, whoever employs them.
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32. Within what radius may a Wyoming farm or ranch vehicle over 26,001 pounds be operated on a Class C license instead of a CDL?
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Answer B: Within a 150 air-mile radius
Wyoming exempts farm and ranch vehicles from the CDL requirement when they are controlled and operated by a farmer or rancher in agricultural operations within a 150 air-mile radius.
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33. Cargo carried inside the cab must never do which of these?
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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.
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34. 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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35. 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.
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36. Why must the downshift be finished before you reach a steep downgrade or a sharp curve rather than during it?
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Answer D: Because once your speed is too high you may not get into any gear at all
If you wait until speed has built up, the lower gear may refuse to engage and you can be left in neutral with no engine braking at all.
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37. Why should you never shift gears while crossing railroad tracks?
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Answer A: You could miss the gear or stall and be stuck on the tracks
A stalled or coasting vehicle on the tracks has no way to clear quickly, so choose the gear before the crossing and do not shift until you are across.
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38. The only way into a customer yard forces you to back toward the right, or blind, side of the vehicle. What should you do?
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Answer D: Use a helper and get out to check the path more often than you normally would
Blind side backing is allowed but far riskier, so it calls for a spotter you can see and for repeated checks of the path on foot.
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39. Why does a load of hanging meat in a refrigerated trailer require special care in curves?
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Answer D: The meat swings and has a high center of gravity, which makes the trailer unstable
Hanging meat is heavy, sits high and swings, so the trailer can tip in a curve or on a ramp taken at normal speed.
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40. When a helper guides you while backing, what should be agreed on before you start?
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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.
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41. 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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42. 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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43. You have a part load that fills only a third of a long trailer. How should it be placed?
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Answer C: Spread out and centerd side to side, so the weight sits over the axles
A part load is spread over as much of the floor as possible and kept centerd, so no axle is overloaded and the vehicle stays balanced from side to side.
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44. What happens to braking performance if oil or grease reaches a brake lining?
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Answer B: That brake loses much of its effect and the vehicle can pull to one side
A contaminated lining cannot grip the drum, so that wheel contributes little braking and the vehicle pulls toward the side that is still working.
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45. 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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46. Why should the mirrors be checked repeatedly while you make a tight turn?
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Answer C: To watch the rear of the vehicle clear other vehicles and objects
In a long vehicle the rear wheels cut inside the path of the front wheels, so only the mirrors show whether the rear is clearing curbs, poles and other vehicles.
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47. Since July 2025, what does Wyoming impose on a commercial license or commercial learner permit holder under 21 found in physical control of a vehicle at an alcohol concentration of 0.02 percent or more?
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Answer C: A mandatory one-year commercial motor vehicle disqualification
An amendment to W.S. 31-7-305 effective 1 July 2025 added a mandatory one-year commercial motor vehicle disqualification for holders under 21 at 0.02 percent or more.
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48. What is axle weight?
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Answer C: The weight carried to the ground by one axle or one set of axles
Axle weight describes how the load is shared among the axles that carry it to the road, not how much the whole vehicle weighs.
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49. 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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50. 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.