North Dakota NDDOT CDL General Knowledge Practice Test 4
Test 4 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 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.
-
2. A vehicle becomes unsafe while you are already on the road. What does the federal rule allow?
Show answer
Answer A: Continuing only to the nearest place where repairs can safely be made
If stopping where you are would be more dangerous than moving, the rule allows you to reach the nearest place where the vehicle can safely be repaired, and no further.
-
3. A strap is a little too long, so a driver ties a knot in it to take up the slack. Is that acceptable?
Show answer
Answer C: No, tiedowns must not contain knots
A knot destroys the rated strength of a tiedown, so the rules do not allow knotted securement devices; the excess is taken up by the winch or ratchet instead.
-
4. You are given a ratchet strap with a deep cut along one edge. What should you do?
Show answer
Answer C: Do not use it; a damaged tiedown cannot be relied on to hold its rated load
Cuts, burns, knots and broken stitching weaken a strap far below its marked working load limit, so it must be taken out of service.
-
5. On a tractor with a sliding fifth wheel, what does moving the fifth wheel forward do?
Show answer
Answer A: Puts more of the trailer weight onto the steering axle
Moving the coupling point forward transfers weight from the drive axles to the steering axle, which is how a driver corrects a drive axle that is over the limit.
-
6. Experienced commercial drivers scan the road ahead by roughly how much travel time?
Show answer
Answer B: About 12 to 15 seconds
Looking 12 to 15 seconds ahead gives a heavy vehicle enough room to slow or change lanes smoothly instead of reacting late.
-
7. An overpass you have driven under before now has a fresh layer of pavement on the road below it. Why does that matter?
Show answer
Answer B: The new layer raises the road and reduces the clearance
Repaving lifts the road surface, so the real clearance under a structure can be less than the height posted on it.
-
8. After starting a trip, when must a driver first re-inspect the cargo and the devices holding it?
Show answer
Answer A: Within the first 50 miles
Federal rules require a check of the load and its securement within the first 50 miles, because settling and vibration loosen straps and chains early in a trip.
-
9. The temperature is around freezing and the road looks wet. What is a practical way to tell whether it is icy?
Show answer
Answer C: Check for ice building up on the mirrors, antenna or the front of the vehicle
Ice that forms on the mirror, antenna or windshield is a warning that the road surface is freezing too, and black ice can look like a wet road.
-
10. How is free play in the steering wheel measured during the inspection?
Show answer
Answer B: By turning the wheel until the front wheels just start to move and noting the movement
Play is the movement at the rim that produces no movement at the road wheels, so it is measured by turning until the wheels first respond.
-
11. What should a driver assume about the height posted at a bridge or an overpass?
Show answer
Answer B: That it may be wrong, because repaving or packed snow can leave less clearance than the sign shows
Resurfacing and packed snow raise the road under the structure, so the real clearance can be lower than the posted figure.
-
12. When should the horn of a commercial vehicle be used?
Show answer
Answer C: Only when it is needed to avoid a crash
An air horn is loud enough to startle other road users, so it is a warning device rather than a way to comment on other drivers.
-
13. Using the snub braking method on a downgrade, when does the driver release the brakes?
Show answer
Answer A: After speed has dropped about 5 mph below the safe speed
The driver brakes firmly to about 5 mph under the chosen safe speed, releases to let the brakes cool, then repeats when the safe speed returns.
-
14. 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.
-
15. You want to check whether a tire on your truck is properly inflated. What is the correct method?
Show answer
Answer A: Measure the pressure with a tire gauge
Only a tire gauge tells you the actual pressure; a tire can look and sound normal while being badly underinflated.
-
16. You need to pull off onto the shoulder because of a problem with the load. How should you communicate that to other drivers?
Show answer
Answer D: Signal the move, then switch on the four-way flashers once stopped
Other drivers need a signal before you leave the lane and a clear warning once the vehicle is stopped near the traffic lanes.
-
17. A chain rated at 6,600 pounds is fitted with a hook rated at 4,700 pounds. What is the working load limit of that assembly?
Show answer
Answer A: 4,700 pounds, the rating of the weakest part
An assembly is only as strong as its weakest component, so hooks, binders and links all count and the lowest rating governs.
-
18. Why are the windshield wipers on the pre-trip list even before a trip in fine weather?
Show answer
Answer C: Because weather can change and a wiper failure leaves the driver without a clear view
Rain, spray or mud can arrive at any point in a long trip, and a wiper that fails then leaves the driver with no way to clear the windshield.
-
19. A company mechanic serviced your truck this morning and signed the work order. Do you still have to inspect the vehicle?
Show answer
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.
-
20. 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.
-
21. How should a driver use brakes fitted with an antilock system during an emergency stop?
Show answer
Answer C: Brake as usual and keep enough pressure to stay in control while steering around the hazard
The system only works when the brakes are applied hard enough for it to act, so the driver keeps pressure on and steers while the system prevents lockup.
-
22. 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.
-
23. 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.
-
24. What happens to braking performance if oil or grease reaches a brake lining?
Show answer
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.
-
25. When should a driver add space beyond the basic following distance rule?
Show answer
Answer D: On slippery roads and whenever visibility is poor
The seconds rule is a minimum for good conditions, so rain, snow, darkness and heavy traffic all call for more space than that.
-
26. 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.
-
27. You are dropping a loaded trailer in a yard. How far should the landing gear be lowered?
Show answer
Answer A: Until the pads make firm contact and the trailer weight is just off the fifth wheel
Cranking down until the gear is firmly on the ground and just lifting the load off the fifth wheel makes the trailer stable and lets the tractor pull out cleanly.
-
28. 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.
-
29. 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.
-
30. You are backing with a helper guiding you and the helper drops out of sight in your mirror. What should you do?
Show answer
Answer B: Stop until you can see the helper again
If you cannot see the helper you cannot receive a signal to stop, so the only safe action is to halt until visual contact is restored.
-
31. 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.
-
32. 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.
-
33. In North Dakota, what must be completed before a hazardous materials knowledge test may be taken?
Show answer
Answer D: The applicant must hold the North Dakota commercial license and pass the TSA security threat assessment
North Dakota requires a commercial permit holder to obtain the North Dakota commercial license and to pass the fingerprint-based security threat assessment before becoming eligible for the hazardous materials knowledge test.
-
34. What minimum age does North Dakota require to drive a commercial vehicle across state lines?
Show answer
Answer B: 21 years old
North Dakota requires a driver to be at least 21 to operate a commercial vehicle in interstate commerce; below that age the operation is limited to within the state.
-
35. What is the minimum tread depth required in every major groove of a steering axle tire?
Show answer
Answer D: 4/32 inch
Federal rules set a higher tread minimum for front steering tires than for other positions because a steering tire failure is far harder to control.
-
36. After coupling, where should the fifth wheel release handle be?
Show answer
Answer A: In the locked position with the safety latch in place
The handle must be pushed in and latched, because a handle left out means the jaws can open and release the trailer while you are driving.
-
37. 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.
-
38. You are asked to drive a truck loaded with enough hazardous materials to require placards. What must you have?
Show answer
Answer C: A hazardous materials endorsement on your commercial driver license
Driving a vehicle that must be placarded requires the H endorsement, which involves a separate knowledge test and a security background check.
-
39. 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.
-
40. A 40 foot straight truck and a 70 foot tractor-trailer make the same right turn. Which needs more room and why?
Show answer
Answer B: The tractor-trailer, because the longer the vehicle the farther inside the rear wheels track
Off-tracking grows with the distance between the front and rear axles, so the longer combination cuts the corner much more sharply and needs extra room.
-
41. Does the federal texting ban apply to a company dispatching device mounted in the cab?
Show answer
Answer B: Yes, entering or reading text on it while driving is banned
The rule is written around the act of reading or entering text on any electronic device, not around who owns the device.
-
42. After starting the engine, how quickly should the oil pressure gauge come up to its normal range?
Show answer
Answer B: Within a few seconds
Oil pressure should build within seconds of starting; if it stays low, the engine is not being lubricated and should be shut down.
-
43. How does a driver measure following distance in seconds?
Show answer
Answer A: Wait for the vehicle ahead to pass a fixed roadside object, then count the seconds until the front of your vehicle reaches the same object
Counting from the moment the vehicle ahead passes a landmark until you reach it turns a gap you cannot judge in feet into a number of seconds.
-
44. 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.
-
45. During the walkaround you notice one tire on an axle is a radial and the tire next to it is bias-ply. What should you do?
Show answer
Answer B: Treat it as a defect, because radial and bias-ply tires must not be mixed on the same axle
Radial and bias-ply tires flex and grip differently, so mixing them on one axle makes the vehicle handle unpredictably and is not allowed.
-
46. 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.
-
47. 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.
-
48. Which components on a typical engine are driven by belts that must be checked for wear and tension?
Show answer
Answer D: The alternator, the water pump and, on many vehicles, the air compressor
Belts drive accessories such as the alternator, the water pump and the air compressor, so one failed belt can take out charging, cooling or air supply.
-
49. 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.
-
50. How does the working load limit of a tiedown relate to the force that would break it?
Show answer
Answer B: The working load limit is a fraction of the breaking strength and is the figure you use
The working load limit is set well below the point at which the device would fail, and securement is always calculated from the working load limit, never from breaking strength.