North Dakota NDDOT 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 North Dakota test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. 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.
-
2. On the Interstate System, what are the federal maximums for a tandem axle group and for gross vehicle weight?
Show answer
Answer B: 34,000 pounds and 80,000 pounds
The federal Interstate limits allow 34,000 pounds on a tandem axle group and 80,000 pounds gross.
-
3. What is the correct way to make a normal stop?
Show answer
Answer A: Push the brake pedal down gradually and bring the vehicle to a smooth stop
Steady, progressive pedal pressure keeps the vehicle stable and lets the driver behind you react to a predictable slowdown.
-
4. Who may remove an out-of-service sticker from a commercial vehicle?
Show answer
Answer B: Only an authorized person, and only after the defect that caused it has been repaired
The sticker stays on the vehicle until the repairs are made and an authorized person removes it, so nobody can simply peel it off and drive away.
-
5. Which vehicles are most likely to get hung up on a raised railroad crossing?
Show answer
Answer A: Low-slung units such as car carriers and lowboys
Vehicles with low ground clearance or a long wheelbase can bottom out on a humped crossing and become stuck on the tracks.
-
6. 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.
-
7. Loading heavy freight on top of lighter freight has what effect on the vehicle?
Show answer
Answer B: It raises the center of gravity and makes a rollover more likely
A high center of gravity lets the vehicle tip more easily in curves or during a sudden swerve.
-
8. You are taking a tightly curved highway exit ramp in a long combination. Where should the tractor be placed within the lane?
Show answer
Answer D: Toward the outside of the curve, leaving room for the trailer to track inside
Because the trailer wheels cut to the inside of the curve, the tractor has to be kept out toward the outer edge so the trailer does not drop a wheel off the inside edge.
-
9. You are backing a tractor-trailer in a straight line and the trailer starts to drift to the left. What is the standard correction?
Show answer
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.
-
10. 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.
-
11. 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.
-
12. You are strapping down a load with sharp metal edges on a flatbed. What should you use?
Show answer
Answer D: Edge protection between the strap and the sharp edges so the tiedown is not cut
Sharp edges cut or wear through a strap under tension, so edge protectors are required wherever a tiedown could be damaged.
-
13. What is the minimum tread depth for tires in positions other than the steering axle?
Show answer
Answer A: 2/32 inch
Drive and trailer tires must keep at least 2/32 inch of tread in a major groove, measured away from tie bars and fillets.
-
14. Your vehicle begins to hydroplane on a wet road. What should you do?
Show answer
Answer B: Release the accelerator and push in the clutch so the wheels can turn freely and regain grip
Hydroplaning tires are riding on water; slowing without braking lets them settle back onto the road and grip again.
-
15. What information does an inspection decal on a commercial vehicle carry?
Show answer
Answer B: The date of the inspection, where the inspection report is kept, and information identifying the vehicle
The decal shows when the inspection was done, the name and address of the entity that holds the inspection report, and which vehicle it belongs to, so an officer can confirm the inspection at a glance.
-
16. How do objects appear in a convex mirror compared with a flat mirror?
Show answer
Answer B: Smaller and farther away than they really are, while a wider area is shown
A convex mirror shows a wider field but shrinks everything in it, so the driver must remember that vehicles are closer than they look.
-
17. Why does extra weight make a long downgrade more dangerous even when the brakes are in good order?
Show answer
Answer B: Gravity adds to the momentum and the brakes heat up faster
The heavier the vehicle, the more energy the brakes must turn into heat, and heat is exactly what makes brakes fade on a long descent.
-
18. Why should you avoid using your lights to tell a following driver that it is safe to pass you?
Show answer
Answer B: You may misjudge the gap and the driver will act on your signal
The manual warns against signaling others to pass, because the responsibility for a head-on crash then rests on a judgment you could easily get wrong.
-
19. An unblocked crate 4 feet long and weighing 900 pounds needs at least how many tiedowns?
Show answer
Answer D: One
An article 5 feet or less in length and 1,100 pounds or less in weight is covered by a minimum of one tiedown.
-
20. Why can an empty truck need a longer stopping distance than a loaded one?
Show answer
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.
-
21. 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.
-
22. What does restriction K mean on a North Dakota commercial driver license?
Show answer
Answer D: The CDL is valid for intrastate operation only
North Dakota applies restriction K to drivers who self-certify as intrastate or who hold a state waiver, marking the CDL as valid for intrastate operation only.
-
23. Why must cargo also be held down against vertical movement and not only against sliding?
Show answer
Answer D: Because a load that bounces can jump the blocking and slacken its own tiedowns
Rough road makes an unrestrained article lift; every bounce lets it move a little and works the tiedowns loose until nothing is holding it.
-
24. The paperwork shows a weight, but the load looks heavier than you expected. What should you do?
Show answer
Answer C: Weigh the vehicle, since you are the one answerable for driving it overweight
The driver is the one who can be cited for an overweight vehicle, so a doubtful weight is settled on a scale before the trip continues.
-
25. Why is driving much slower than the rest of the traffic dangerous?
Show answer
Answer B: Other drivers must keep passing you, which creates conflicts
Traffic that has to work its way around you produces lane changes and closing speeds, which is why a large speed difference is itself a hazard.
-
26. You are loading lengths of large diameter pipe on a flatbed. What is needed besides the tiedowns?
Show answer
Answer D: Chocks, wedges or cradles that keep the pipe from rolling
Anything that can roll must be prevented from rolling by chocks, wedges, cradles or a similar device that is itself secured so it cannot come out.
-
27. What does it mean to overdrive your headlights at night?
Show answer
Answer D: Driving so fast that you cannot stop within the distance lit by your headlights
You must be able to stop inside the distance you can see; at night that distance is limited by the headlights, so speed must be lowered to match.
-
28. A tire blows out at highway speed. What should the driver do first?
Show answer
Answer C: Hold the steering wheel firmly, stay off the brake and let the vehicle slow down
Braking while a tire is gone can pull the vehicle out of line, so the driver keeps it straight and lets speed fall before easing off the road.
-
29. During a stop you find a package in the trailer leaking an unknown chemical. What should you do?
Show answer
Answer C: Keep clear, keep others away and get help without touching the package
A driver without the training and equipment does not handle a leak; the job is to protect people from the material and get qualified help to the scene.
-
30. How often must every commercial motor vehicle receive a periodic inspection?
Show answer
Answer C: At least once every twelve months
Federal rules require each commercial motor vehicle to pass a periodic inspection at least once in every twelve month period.
-
31. What happens to braking distance when speed is doubled?
Show answer
Answer C: It becomes about four times longer
Braking distance grows with the square of speed, so doubling the speed multiplies both the braking distance and the force of an impact by about four.
-
32. Your brakes are starting to fade on a mountain downgrade and a sign shows an escape ramp one mile ahead. What should you do?
Show answer
Answer B: Plan to use the ramp instead of trying to reach the bottom
Fading brakes on a grade only get worse, and the ramp exists precisely so a driver does not have to gamble on the rest of the descent.
-
33. How does a front tire failure usually feel to the driver?
Show answer
Answer D: The steering suddenly becomes heavy and pulls to one side
A failed front tire loads the steering and makes the wheel feel heavy, while a rear tire failure shows up as the back end swaying.
-
34. What is the most common cause of a front-wheel skid, where the vehicle keeps going straight even though you turn the wheel?
Show answer
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.
-
35. What does the commercial driver manual tell you to do with the parking brake when you leave your vehicle?
Show answer
Answer B: Apply the parking brake every time you leave the vehicle
The manual is explicit that the parking brake goes on whenever the driver leaves the vehicle, because once nobody is at the controls it is the only thing holding it.
-
36. 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.
-
37. The combined working load limit of the tiedowns on a load must equal at least what share of the cargo weight?
Show answer
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.
-
38. 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.
-
39. 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.
-
40. 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.
-
41. You are loading a flatbed that has no sides or bulkheads. How must the cargo be held?
Show answer
Answer D: By tiedowns, blocking or bracing, since there are no walls to keep it from shifting or falling off
Open decks depend entirely on securement devices; every article must be tied down or otherwise immobilized so it cannot move, spill or fall.
-
42. You are about to back across a quiet street into a driveway. Which of these is good practice before you start to move?
Show answer
Answer B: Turn on the four-way flashers and sound the horn to alert anyone nearby
Warning other road users and pedestrians before a reverse maneuver gives them the chance to stop or move clear before the vehicle starts back.
-
43. Under North Dakota's license classes, when must a Class D holder be at least 18 years old?
Show answer
Answer C: When the combined weight of vehicle and trailer exceeds 26,000 pounds
North Dakota's Class D definition notes that the holder must be 18 years of age or older if the combined weight of the vehicle and what it tows exceeds 26,000 pounds.
-
44. What tells a driver when to shift up in a vehicle with a manual transmission?
Show answer
Answer C: Engine speed in rpm together with road speed
Shift points are judged from engine rpm and road speed, using the operating range the manufacturer specifies for that engine.
-
45. A delivery van is stopped in the right lane ahead with its flashers on. What should you expect?
Show answer
Answer C: Someone may step into your lane from in front of it
A stopped delivery vehicle hides the space in front of it, and that is exactly where a person carrying a package is likely to walk out.
-
46. At highway speed, looking 12 to 15 seconds ahead means looking about how far down the road?
Show answer
Answer B: About a quarter of a mile
Twelve to fifteen seconds of travel is roughly a quarter of a mile at highway speed, while the same amount of time is about one block in slow city traffic.
-
47. What is the correct order for a basic double clutch upshift?
Show answer
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.
-
48. Why must you never coast down a hill in neutral or with the clutch pushed in?
Show answer
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.
-
49. What is the purpose of an escape ramp on a mountain grade?
Show answer
Answer C: To stop a runaway vehicle without injuring the driver
Escape ramps use soft material or a steep upgrade to bring a vehicle with failed brakes to a controlled stop.
-
50. During the walkaround you notice a bulge in the sidewall of a trailer tire. What does it indicate?
Show answer
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.