Washington DOL CDL General Knowledge Practice Test 8
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. An unblocked crate 4 feet long and weighing 1,500 pounds needs at least how many tiedowns?
Show answer
Answer A: Two
A short article that weighs more than 1,100 pounds requires at least two tiedowns even though it is under 5 feet long.
-
2. The coolant temperature gauge climbs above its normal range on a long grade. What is the correct response?
Show answer
Answer C: Stop when it is safe to do so and find the cause before going on
Rising coolant temperature signals a fault such as a lost belt, a leak or a blocked radiator, and continuing can turn a repair into a destroyed engine.
-
3. What makes a brake hose or air line a defect during the walkaround?
Show answer
Answer D: It is cracked, worn, kinked, or rubbing against another part
A chafed or cracked line can burst under pressure and take the braking on that circuit with it, so damage and rubbing points must be corrected.
-
4. 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.
-
5. When should a driver select the gear for a long, steep downgrade?
Show answer
Answer B: Before starting down the grade
The low gear has to be chosen before the descent, because a heavy vehicle gaining speed may refuse to shift down at all.
-
6. 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.
-
7. 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.
-
8. 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.
-
9. 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.
-
10. What should the ammeter or voltmeter show once the engine is running?
Show answer
Answer D: A reading in the normal charging range
With the engine running, the alternator should be charging; a discharge reading or an abnormal charge level means an electrical fault.
-
11. How long must a Washington Commercial Learner Permit be held before taking a skills test?
Show answer
Answer B: A minimum of 14 days
Washington requires the Commercial Learner Permit to be held for a minimum of 14 days before the skills test for the vehicle type and endorsements the applicant intends to operate.
-
12. 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.
-
13. 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.
-
14. 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.
-
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. Why should water never be used on an electrical fire or a gasoline fire?
Show answer
Answer C: It spreads the fuel and conducts the current
Water carries current back to the person holding the hose and floats burning fuel outward, which is why a B:C rated extinguisher is carried instead.
-
17. 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.
-
18. During a right turn in a tractor-trailer, what are you looking for in the right hand mirror?
Show answer
Answer B: Whether the trailer will clear the curb and whether anything has moved alongside you
The right mirror is what tells you how close the trailer wheels are running to the curb and whether a vehicle or a cyclist has slipped into the space on your right.
-
19. Total stopping distance is made up of which parts?
Show answer
Answer A: Perception distance, reaction distance and braking distance
The vehicle travels while the hazard is recognized, while the driver moves to the pedal, and again while the brakes slow the vehicle.
-
20. When must a post-trip inspection be made?
Show answer
Answer D: At the end of each day the driver operates the vehicle
The post-trip inspection closes out each driving day so that anything found is recorded before the vehicle is handed to the next driver.
-
21. What is the risk when too little weight rests on the drive axles?
Show answer
Answer A: Poor traction, so the drive wheels spin easily on wet or slippery surfaces
Traction depends on weight pressing the driving tires onto the road, so a light drive axle spins on wet, snowy or loose surfaces.
-
22. A straight truck has a long body behind the rear axle. What happens to that overhang in a sharp left turn?
Show answer
Answer D: It swings out to the right and can strike a vehicle or an object on that side
Body that hangs behind the rear axle swings the opposite way to the turn, so the tail of the truck sweeps out into the next lane or over the curb.
-
23. While you are driving, what should you do to catch a developing problem with the vehicle?
Show answer
Answer A: Check the gauges regularly and pay attention to unusual sounds, smells or vibrations
Inspection continues during the trip: gauges, mirrors and your senses can reveal a problem long before a warning light does.
-
24. What is the driver responsible for when a load is covered with a tarp?
Show answer
Answer C: Fastening it so it cannot flap free, block a mirror, or come off in the wind
A tarp that works loose can tear away, block the driver view or the view of others, and become a hazard for the traffic behind.
-
25. 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.
-
26. 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.
-
27. What are you checking when you look at the batteries during the engine compartment inspection?
Show answer
Answer D: That they are securely mounted, the connections are tight and free of corrosion, and the caps are in place
Loose or corroded batteries can fail or short out, so the mount, cables, terminals and vent caps are all part of the check.
-
28. 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.
-
29. Cargo carried inside the cab must never do which of these?
Show answer
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.
-
30. Why should you never shift gears while crossing railroad tracks?
Show answer
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.
-
31. On a set of dual tires, which condition must be reported as a defect?
Show answer
Answer D: The two tires are touching each other or rubbing on part of the vehicle
Duals that touch each other or the vehicle overheat and wear quickly, so they must be separated by proper spacing and inflation before driving.
-
32. 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.
-
33. Why should a driver avoid shifting gears in the middle of a turn at an intersection?
Show answer
Answer D: Shifting during the turn takes a hand off the wheel and can cost you control
Pick the gear before you begin turning; shifting in the turn removes a hand from the wheel and can interrupt power just when you need steady control.
-
34. The car in the next lane still has snow covering most of its windows. What should you assume?
Show answer
Answer C: That driver cannot see you and may move into your lane
A driver whose view is blocked cannot see the vehicles around, so you should assume you are invisible and stay out of that vehicle path.
-
35. The brake pedal goes to the floor in a vehicle with hydraulic brakes. What can you do to build some braking pressure?
Show answer
Answer B: Pump the brake pedal rapidly, which may bring back enough pressure to slow the vehicle
Pumping can restore some hydraulic pressure; along with downshifting and the parking brake it is one of the ways to stop when the pedal fails.
-
36. What must a written driver vehicle inspection report cover at the end of the day?
Show answer
Answer C: Any defect or deficiency that would affect safety or could cause a mechanical breakdown
The report identifies the vehicle and lists defects that affect safe operation or could lead to a breakdown, so they are repaired before the next trip.
-
37. A commercial driver is convicted of two serious traffic violations within three years. What is the result?
Show answer
Answer D: Disqualification for 60 days
Two serious traffic violations in a three year period bring a 60 day disqualification, and a third in the same period raises it to 120 days.
-
38. What is a bulkhead in a cargo body used for?
Show answer
Answer D: To divide the space and stop cargo from moving into another part of the body
A bulkhead is a solid partition that separates one part of the load space from another and blocks the cargo from moving past it.
-
39. What should be done before a night trip to get the most from your headlights?
Show answer
Answer C: Clean the windshield, the mirrors and the lights
Dirt on glass and lenses cuts both the light you throw down the road and the light that reaches your eyes, so cleaning is the cheapest night safety measure there is.
-
40. 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.
-
41. You are hauling a sealed trailer and have been told in writing not to open it. How does that affect the en route cargo checks?
Show answer
Answer C: You do not have to inspect the cargo itself, but the vehicle and weight are still yours
The en route cargo inspection rule does not apply to a driver of a sealed vehicle who has been ordered not to open it, but every other responsibility, including legal weight, remains.
-
42. Why does a load of hanging meat in a refrigerated trailer require special care in curves?
Show answer
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.
-
43. 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.
-
44. How many vehicles must a person have registered in Washington to qualify as a self-insurer instead of carrying a policy?
Show answer
Answer C: More than 25
Washington allows a person with more than 25 vehicles registered in their name to qualify as a self-insurer.
-
45. 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.
-
46. Which steering system findings count as defects during the inspection?
Show answer
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.
-
47. What is the purpose of the torque rods or radius rods you check on the suspension?
Show answer
Answer A: They hold the axle in alignment with the frame under braking and acceleration
Torque rods resist the twisting and fore and aft forces on the axle, so a cracked or missing rod lets the axle move out of alignment.
-
48. 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.
-
49. A tire has a cut deep enough to expose the body ply or the belt material. What does that mean?
Show answer
Answer D: The vehicle must not be driven on that tire
Once the structural plies are exposed the casing has lost its strength, and federal rules treat that tire as unfit for the road.
-
50. 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.