Washington DOL CDL General Knowledge Practice Test 5
Test 5 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 Washington test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
-
1. How should the steering wheel be held when driving a large vehicle?
Show answer
Answer D: Firmly with both hands, placed on opposite sides of the wheel
Both hands on opposite sides give the leverage and control needed if a tire drops off the pavement or the wheel is jolted.
-
2. What does the gross vehicle weight rating of a vehicle describe?
Show answer
Answer A: The maximum loaded weight of that single vehicle, as specified by the manufacturer
The rating is the manufacturer figure for the loaded weight of one vehicle, so it is a limit fixed in advance rather than a measurement of the load on board today.
-
3. When speed doubles, what happens to braking distance?
Show answer
Answer D: It becomes roughly four times as long
Braking distance rises with the square of speed, so twice the speed needs about four times the distance to stop.
-
4. You are hauling an open box of loose gravel. What does that load require?
Show answer
Answer A: A cover, so that material cannot blow off or spill onto the road
Loose material that can be blown or spilled has to be covered so it does not come out of the body and strike traffic behind.
-
5. Where is the yellow antilock brake malfunction lamp on a trailer, and what does it mean if it stays lit?
Show answer
Answer D: On the left side, at the front or rear corner, and it means the antilock function may not be working
Trailers carry the yellow lamp on the left side, and a lamp that stays on after the bulb check means the antilock function may be lost even though the normal brakes still work.
-
6. What does the tachometer on the dashboard of a heavy truck show?
Show answer
Answer D: How fast the engine is turning, in revolutions per minute
The tachometer reads engine speed in rpm, which is what a driver uses to judge shift points in a vehicle with a manual transmission.
-
7. You are not certain that your loaded vehicle will clear a low overpass. What should you do?
Show answer
Answer A: Take another route rather than risk it
There is no safe way to guess at a clearance, and striking a bridge endangers everyone on and under it, so the only correct choice is a different route.
-
8. During the walkaround you find the reflective conspicuity tape along the trailer caked with road grime. What should you do?
Show answer
Answer B: Clean it, because dirty reflective material cannot make the trailer visible at night
Reflective sheeting only works if light can reach it and bounce back, so a dirty strip leaves the trailer effectively unmarked to approaching traffic.
-
9. 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.
-
10. Why should a driver avoid traveling alongside another vehicle for any length of time?
Show answer
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.
-
11. 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.
-
12. 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.
-
13. How do you confirm that the coupling is locked before pulling out of the yard?
Show answer
Answer D: By locking the trailer brakes and pulling gently forward against them
The tug test loads the coupling in the direction that would pull it apart, so if the jaws are not closed on the kingpin you find out at walking pace.
-
14. Where are the OVERSIZE LOAD signs normally carried on a vehicle moving under such a permit?
Show answer
Answer A: On the front and the rear of the vehicle
The warning signs face the traffic that meets the load and the traffic that comes up behind it, so they go on the front and the rear.
-
15. What is generally the safest speed in dense but freely moving highway traffic?
Show answer
Answer D: The speed of the traffic around you, up to the posted limit
Crashes rise with the difference between your speed and the traffic around you, so moving with the flow within the legal limit is safest.
-
16. Which parts of total stopping distance can a driver shorten simply by staying alert and looking far ahead?
Show answer
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.
-
17. 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.
-
18. You are inspecting the vehicle alone and need to confirm that the stop lights work. Which method is correct?
Show answer
Answer A: Have a helper press the brake pedal, or apply the brake in a way that keeps it on while you check from outside
Stop lights are checked from outside the vehicle while the brakes are applied, so a helper or a brake held on is needed.
-
19. If an intersection has two lanes marked for left turns, which one should a large vehicle use?
Show answer
Answer D: The right hand of the two turning lanes
The outside turning lane leaves room for the rear of the vehicle to swing without striking a vehicle in the adjacent lane.
-
20. Why must the downshift be finished before you reach a steep downgrade or a sharp curve rather than during it?
Show answer
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.
-
21. 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.
-
22. Why is a sudden, sharp lane change dangerous in a loaded heavy vehicle?
Show answer
Answer D: The vehicle can lean far enough to roll over, especially when the load sits high
A quick swerve throws the weight of a tall, heavy load sideways, and a rollover can begin before the tires ever slide.
-
23. 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.
-
24. 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.
-
25. What speed and gear should be used when backing a large vehicle?
Show answer
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.
-
26. You need fuel and the canopy over the pumps is low. What is the safe way to handle the clearance?
Show answer
Answer B: Stop and check the height at the entrance and at the way out before committing
Clearance can differ at the entry, under the canopy and at the exit, and a sloping approach changes the effective height, so both ends have to be checked.
-
27. 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.
-
28. 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.
-
29. When should a lower gear be selected for a long downgrade?
Show answer
Answer D: Before you start down the hill
The gear is chosen at the top, while speed is still low, because a heavy vehicle already rolling fast may not go into a lower gear at all.
-
30. What frame defects are you looking for during the walkaround?
Show answer
Answer A: Cracks, bends or broken cross members
The frame carries the whole load, so cracked or bent rails and broken cross members are serious structural defects.
-
31. 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.
-
32. Why does a load need to be balanced from side to side?
Show answer
Answer B: Because a heavy side raises the rollover risk and can overload the tires and springs on that side
An uneven load tips the balance of the vehicle in curves and pushes the tires and suspension on the loaded side past their rating.
-
33. A hazard suddenly appears ahead and you must act. Which is usually the faster way to avoid it in a heavy vehicle?
Show answer
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.
-
34. 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.
-
35. How can a driver restart the 60 or 70 hour on-duty limit?
Show answer
Answer B: Take 34 or more consecutive hours off duty
A period of 34 or more consecutive hours off duty resets the 60 or 70 hour calculation so the driver can begin a new period.
-
36. What are you looking for on the brake drums during the walkaround?
Show answer
Answer B: Cracks, dents and any oil or grease that has reached the friction surface
A cracked or badly scored drum can break apart under braking heat, and oil or grease on the friction surface destroys the braking effort at that wheel.
-
37. What is checked about the engine cooling system during the engine compartment inspection?
Show answer
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.
-
38. How are the headlights, marker lights and turn signals checked during the seven-step inspection?
Show answer
Answer A: The engine is shut off, the parking brake is set, the lights are switched on and then checked from outside the vehicle
The lights are switched on with the vehicle secured, then the driver walks around and confirms each lamp actually works and is clean.
-
39. 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.
-
40. You have stopped and a pedestrian is waiting to cross in front of your truck. Why should you not wave the person across?
Show answer
Answer C: Another driver may not stop, and your wave sends the person into danger
You cannot control what drivers in the other lanes will do, so you should not invite a pedestrian into a lane you do not command.
-
41. What should you check about the tire valve stems during the walkaround?
Show answer
Answer D: That the stems are not cut, cracked or leaking and the caps are in place
A split stem or a missing cap lets air escape or lets dirt into the valve, and either one can flatten a tire between stops.
-
42. You are backing into a yard where electrical wires cross overhead. What is the main concern?
Show answer
Answer C: The wires may hang lower than the top of your vehicle
Overhead space has to be checked like any other space around the vehicle, because wires and cables are often lower than they look from the cab.
-
43. 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.
-
44. You find one lug nut missing from a wheel that has ten studs. What should you do?
Show answer
Answer C: Treat it as a defect and have it repaired before the vehicle is driven
Every missing fastener loads the others more heavily, and wheel separations usually begin with one nut that nobody replaced.
-
45. Why must exhaust components be checked for contact with other parts of the vehicle?
Show answer
Answer B: Hot exhaust parts touching fuel lines, tires or wiring can start a fire
Exhaust pipes run hot enough to ignite fuel and melt insulation, so they must be kept clear of the fuel system, the tires and the electrical harness.
-
46. Some commodities have their own detailed securement rules on top of the general ones. Which list is made up of such commodities?
Show answer
Answer C: Logs, metal coils, paper rolls, concrete pipe and crushed vehicles
The cargo securement rules add specific requirements for particular commodities, including logs, dressed lumber, metal coils, paper rolls, concrete pipe, intermodal containers, vehicles, crushed cars, roll on containers and large boulders.
-
47. Which of these counts as a serious traffic violation for a commercial driver license holder?
Show answer
Answer C: Speeding 15 miles per hour or more above the limit
Excessive speeding, reckless driving, improper lane changes, following too closely and texting while driving are all serious traffic violations.
-
48. Your truck has a backup alarm that sounds whenever reverse is selected. What may a driver rely on it for?
Show answer
Answer D: Very little; it warns some people but cannot show you what is behind the vehicle
An alarm may not be heard over yard noise or by someone wearing hearing protection, so it never replaces looking at the path yourself.
-
49. 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.
-
50. 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.