Wisconsin WisDOT DMV CDL General Knowledge Practice Test 3
Test 3 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 Wisconsin test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. Why is a quick lane change particularly risky with a load of hanging meat or of livestock?
Show answer
Answer A: The load swings or leans and can keep pushing the trailer after you straighten out
A swinging or leaning load keeps moving after the vehicle has finished the maneuver, so its momentum acts on the trailer at the worst moment.
-
2. Why does the commercial driver manual tell you to look far down the road instead of only at the vehicle ahead?
Show answer
Answer D: So you can adjust smoothly instead of braking hard at the last moment
A heavy vehicle cannot react quickly, so early information lets you slow gradually rather than make a sudden stop or swerve.
-
3. Why should the radio, the fan and other noisy equipment be switched off during a required stop at a railroad crossing?
Show answer
Answer C: So that an approaching train can be heard
The rules require the driver to look and listen along the track, and on a double track crossing a passing train can hide a second one, so hearing matters as much as seeing.
-
4. How long does a Wisconsin CDL holder have to get a replacement license after an address change?
Show answer
Answer C: 10 days
Wisconsin requires a Commercial Driver License holder to obtain a replacement license within 10 days of an address change.
-
5. What should you check about the fuel tank during the walkaround?
Show answer
Answer A: That it is securely mounted, the cap is on tight and there are no leaks
A loose tank or a missing cap can spill fuel, and any fuel leak is a fire hazard that makes the vehicle unsafe to drive.
-
6. Federal rules forbid operating a commercial vehicle in which condition?
Show answer
Answer C: In a condition likely to cause a crash or a breakdown
A defect that makes a crash or a breakdown likely has to be corrected before the vehicle is driven, not reported at the end of the trip.
-
7. Which wheel or rim condition must be treated as a defect during the walkaround?
Show answer
Answer C: Cracks, illegal welded repairs, or missing and loose lug nuts
Cracked or welded rims and missing or loose fasteners can let a wheel separate from the vehicle and must be corrected before driving.
-
8. What condition should the fifth wheel be in before you back under a trailer?
Show answer
Answer C: Jaws open, plate greased, and the fifth wheel tilted down toward the rear
The jaws have to be open to take the kingpin, the plate must be lubricated to prevent hard steering, and the fifth wheel is tilted down at the rear so the trailer apron can ride up onto it.
-
9. What Wisconsin commercial vehicle qualifies as Class B rather than Class A?
Show answer
Answer C: A single vehicle rated over 26,000 pounds that either tows nothing or tows a unit rated 10,000 pounds or less
Wisconsin defines Class B as a single vehicle over 26,000 pounds, whether it tows nothing or only tows a unit of 10,000 pounds or less.
-
10. 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.
-
11. Why should a long vehicle never swing out to the left before starting a right turn?
Show answer
Answer D: Another driver may read it as a left turn or pass on your right
Swinging left opens a gap on your right that a car will move into, and it also sends a false message about which way you are going.
-
12. Which step of the seven-step inspection method comes immediately after checking the engine compartment?
Show answer
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.
-
13. For a Wisconsin driver holding a regular or CDL license, how does the suspension length grow as demerit points climb from 12 up to 30 or more?
Show answer
Answer A: It steps up through four tiers: 2 months, 4 months, 6 months, then 1 year
Wisconsin uses four suspension tiers for a regular or CDL license holder: 2 months for 12 to 16 points, 4 months for 17 to 22, 6 months for 23 to 30, and 1 year for 30 or more.
-
14. Two vehicles of exactly the same length make a right turn, one gently and one very tightly. What is the effect on off-tracking?
Show answer
Answer A: Turning more sharply increases off-tracking, so the tight turn needs more room
Off-tracking depends on both the length of the vehicle and the sharpness of the turn; a tighter corner brings the rear wheels further inside the path of the front wheels.
-
15. An automatic transmission is left in its normal drive position as the vehicle rolls down a long grade. What does it tend to do?
Show answer
Answer A: Shift up as road speed rises, so engine braking falls away
An automatic left in drive keeps upshifting as speed builds, which is the opposite of what you want on a grade; that is why the driver must select a low range.
-
16. What does gross vehicle weight mean, as opposed to gross vehicle weight rating?
Show answer
Answer B: The actual weight of the single vehicle plus everything it is carrying
Gross vehicle weight is what the vehicle actually weighs at that moment; the rating is the maximum the manufacturer allows it to weigh.
-
17. How should a commercial driver treat the speed posted for a curve?
Show answer
Answer B: As a limit set for cars in good conditions, so a heavy or tall load calls for a lower speed
Posted curve speeds are based on passenger vehicles in good conditions, and a tall or heavy load can roll over well below that speed.
-
18. 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.
-
19. What financial benefit does a current or recent service member get when applying for a Wisconsin CDL with a valid military commercial license?
Show answer
Answer B: All CDL issuance and renewal fees are waived
Wisconsin waives all CDL issuance and renewal fees for an applicant who presents a valid military CDL.
-
20. Which factors determine a safe speed for a long, steep downgrade?
Show answer
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.
-
21. With water standing on the road, hydroplaning can begin at speeds as low as what?
Show answer
Answer D: 30 mph
When enough water covers the surface, the tires can ride up on it and lose contact at speeds as low as 30 mph.
-
22. You are pulling away from a curb in a 65 foot combination. Besides traffic, what must you watch?
Show answer
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.
-
23. What happens when too much of the load sits over the steering axle?
Show answer
Answer D: The vehicle becomes hard to steer and the axle and its tires can be damaged
Weight beyond the front axle rating makes the steering heavy and can overload the axle and the tires carrying it.
-
24. An unblocked article is 8 feet long and weighs 900 pounds. How many tiedowns does the federal rule require?
Show answer
Answer B: Two
Only an article that is 5 feet or shorter and 1,100 pounds or lighter can be held with a single tiedown; anything longer than 5 feet needs at least two whatever it weighs.
-
25. 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.
-
26. 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.
-
27. How should speed and gears be handled when approaching a curve?
Show answer
Answer A: Slow to a safe speed and downshift before entering the curve
Braking and shifting are completed before the curve so the vehicle is settled and can pull gently through it without upsetting the load.
-
28. 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.
-
29. You are stopped in a line of traffic behind a car. How much space should you leave in front of you?
Show answer
Answer C: Enough to see where the rear tires of that car meet the road
That amount of space lets you pull around the vehicle ahead if it stalls and absorbs some of the shock if you are struck from behind.
-
30. What are you checking when you pull the engine oil dipstick during the pre-trip?
Show answer
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.
-
31. Wisconsin exempts certain emergency responders from CDL requirements. What must be true of the vehicle they operate for that exemption to apply?
Show answer
Answer B: It must be properly equipped as an authorized emergency vehicle for the response
Wisconsin waives CDL requirements for emergency responders operating a properly equipped authorized emergency vehicle, though the exemption may not carry over to other states.
-
32. The engine has overheated and you need to check the coolant. What is the safe procedure with a pressurized radiator cap?
Show answer
Answer A: Shut the engine off, let the system cool, protect your hands, turn the cap slowly to its first stop so pressure escapes, step back, then remove it
A hot pressurized system throws steam and boiling coolant out of the opening, so the pressure is released slowly and only after the engine has cooled.
-
33. 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.
-
34. Before raising the hood to inspect the engine compartment, what should you do?
Show answer
Answer B: Shut off the engine, set the parking brake and chock the wheels if needed
The engine compartment is inspected with the engine off and the vehicle secured so nothing can move or turn while your hands are inside.
-
35. When turning left, what should a driver of a long vehicle do before beginning the turn?
Show answer
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.
-
36. Under federal rules, which commercial vehicles must stop at every railroad crossing before proceeding?
Show answer
Answer D: Passenger buses and placarded hazardous materials vehicles
Buses carrying passengers and vehicles required to display hazardous materials placards must stop at crossings, while other commercial vehicles slow and check.
-
37. 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.
-
38. How long must a motor carrier keep a driver vehicle inspection report and the certification of repairs?
Show answer
Answer B: Three months
The original report and the certifications attached to it are kept on file for three months from the date the report was prepared.
-
39. How should the headlamps be checked during the pre-trip inspection?
Show answer
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.
-
40. You stop to check the load. Which set of things are you looking at?
Show answer
Answer C: Tight tiedowns, cargo that has not moved, secure doors and tarps still fastened
A cargo check covers the load and everything holding it: whether it has shifted, whether the devices are still tight, and whether doors and covers are still closed and fastened.
-
41. What should you do with the previous driver vehicle inspection report before starting your trip?
Show answer
Answer B: Review it and confirm that listed defects were certified as repaired or as not needing repair
Reviewing the last report and the carrier certification tells you whether reported defects have been corrected before you take the vehicle out.
-
42. 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.
-
43. At what passenger count does a Wisconsin vehicle require a P endorsement or a CDL at all, counting everyone aboard?
Show answer
Answer C: 16 or more people, including the driver
Wisconsin requires a P endorsement, and the underlying vehicle to be treated as commercial, once it is designed or used to carry 16 or more people including the driver.
-
44. You are driving past a park where children are playing close to the curb. What is the correct assumption?
Show answer
Answer A: A child may run into the street without looking
Children act on impulse and do not judge traffic well, so a driver has to expect one to enter the road and slow down in advance.
-
45. A roadside test shows a commercial driver has measurable alcohol in the system but below 0.04. What happens?
Show answer
Answer C: The driver is placed out of service for 24 hours
Any measurable alcohol while on duty results in an immediate 24 hour out of service order, even when the concentration is under the 0.04 limit.
-
46. You are drifting in the lane, yawning constantly and cannot remember the last few miles. What is the only reliable cure?
Show answer
Answer C: Stopping in a safe place and sleeping
Those are classic drowsiness warning signs, and nothing except sleep repays the sleep the body is missing.
-
47. Why must the driver of a large vehicle keep it centered in its lane?
Show answer
Answer B: The vehicle needs the full width of the lane
A commercial vehicle is close to lane width already, so any drift takes part of the vehicle into the next lane or onto the shoulder.
-
48. The rear wheels of your vehicle lock during braking and the rear starts to slide sideways. What should you do first?
Show answer
Answer A: Stop braking so the rear wheels can roll again, then steer quickly in the direction you want to go
Locked wheels have no side grip; releasing the brakes restores traction and then countersteering brings the vehicle back into line.
-
49. 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.
-
50. Your vehicle is stopped just past a hill or curve that hides it from approaching traffic. How should the warning devices be adjusted?
Show answer
Answer A: Move the rearmost device farther back, up to 500 feet, so drivers are warned before the obstruction
When a hill or curve blocks the view, the farthest device is moved back beyond the obstruction so approaching drivers see the warning in time.