Washington DOL 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 Washington test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. You are pulling away from the curb after a delivery. Why is a mirror check needed first?
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Answer B: A cyclist or a vehicle may be coming up alongside you
Traffic and cyclists can arrive alongside a parked vehicle at any moment, so the mirrors must be checked immediately before pulling out.
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2. What blood alcohol concentration disqualifies the holder of a commercial driver license who is operating a commercial vehicle?
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Answer D: 0.04 or higher
Commercial drivers are held to 0.04, half the limit that applies to a driver of a passenger car in the same state.
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3. Where on the road are you most likely to find ice in cold weather?
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Answer B: On bridges, overpasses and shaded stretches, which freeze before the rest of the road
Bridges and overpasses lose heat from above and below, and shaded areas get no sun, so they ice over first and stay icy longest.
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4. What are you checking when you pull the engine oil dipstick during the pre-trip?
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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.
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5. Federal rules require a power unit that is not carrying placarded hazardous materials to have a fire extinguisher with which minimum rating?
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Answer A: One rated 5 B:C or more, or two rated 4 B:C or more each
The minimum is a single unit rated 5 B:C or more, or two units of at least 4 B:C each, which is enough to attack a fuel or electrical fire.
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6. You are backing with a helper guiding you and the helper drops out of sight in your mirror. What should you do?
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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.
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7. A commercial driver is convicted of two serious traffic violations within three years. What is the result?
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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.
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8. At 55 mph, about how far does a vehicle travel during a typical 3/4 second perception time plus 3/4 second reaction time, before the brakes even begin to work?
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Answer C: About 120 feet
Each 3/4 second at 55 mph covers about 60 feet, so perception and reaction together use up roughly 120 feet before braking starts.
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9. What must a Washington applicant have to obtain a CDL or a Commercial Learner Permit?
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Answer D: Be at least 18 years old and hold a valid Washington State driver license
Washington requires a CDL or Commercial Learner Permit applicant to be at least 18 years old and to hold a valid Washington State driver license.
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10. How long is a Washington Commercial Learner Permit valid and how often may it be renewed?
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Answer B: 180 days, renewable only once
A Washington Commercial Learner Permit is valid for 180 days and may only be renewed one time, and banked skills test scores are lost on renewal.
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11. What does the driver check in the final step of the seven-step inspection?
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Answer A: Hydraulic brake leaks where those brakes are fitted, then the parking brake and the service brakes
The last step is done with the engine started: test for hydraulic leaks on vehicles with hydraulic brakes, then prove that the parking brake holds and that the service brakes stop the vehicle.
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12. You are stopped in a line of traffic behind a car. How much space should you leave in front of you?
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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.
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13. Which of these is a major cause of skids in heavy vehicles?
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Answer C: Over-braking, over-steering, over-acceleration or driving too fast for conditions
Skids happen when the tires are asked for more grip than the road can give, which happens through braking, steering or accelerating too hard or simply too much speed.
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14. When is a road surface usually most slippery during a rain shower?
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Answer A: Just after the rain starts, when water mixes with oil and dirt on the surface
The first rain lifts oil and dust into a slick film that has not yet been washed away, so the road is more slippery than it will be later.
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15. Loading heavy freight on top of lighter freight has what effect on the vehicle?
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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.
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16. You drop your phone on the floor of the cab while driving. What do federal rules require?
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Answer A: Leave it, because reaching for it while driving is banned
Federal rules forbid reaching for a mobile device in any way that takes the driver out of a seated, belted driving position.
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17. How long must a Washington Commercial Learner Permit be held before taking a skills test?
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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.
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18. What is checked about the clutch and the gearshift during the in-cab inspection?
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Answer D: That the clutch free play is within the range the manufacturer specifies
Too little or too much clutch free play causes slipping or dragging, either of which can leave the driver unable to select the gear a hill demands.
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19. You have chosen 40 miles per hour as your safe speed for a downgrade. How should the brakes be used?
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Answer A: Brake firmly to about 35, release, and repeat at 40
Proper technique is firm application to about 5 miles per hour below the safe speed, then full release so the brakes cool before the next application.
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20. An angry driver has cut in front of you and is now braking hard to provoke you. What is the safest response?
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Answer D: Drop back, avoid eye contact and let the driver go
Giving an aggressive driver space and no response removes the conflict, while any answering gesture invites escalation you cannot control in a heavy vehicle.
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21. Why does the manual insist on a firm grip with both hands on opposite sides of the steering wheel?
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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.
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22. A driver is tailgating you, honking and making gestures. What is the best response?
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Answer A: Do not make eye contact, ignore the gestures and give the driver room to get past
Engaging an aggressive driver only escalates the situation; the safest move is to stay calm, avoid eye contact and let the driver get by.
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23. What is the standard reissue fee to reinstate a Washington driver's license after a suspension unrelated to DUI?
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Answer D: $75
Washington's standard reissue fee to reinstate a suspended license is $75.
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24. The rear wheels of your vehicle lock during braking and the rear starts to slide sideways. What should you do first?
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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.
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25. You are hauling livestock and the trailer is only partly full. What should be done?
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Answer A: Use false bulkheads or partitions to keep the animals bunched together
Animals that can move around shift the center of gravity, so a partial load is bunched together with partitions to limit how far the weight can move.
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26. Compared with a fully loaded one, an empty truck under hard braking will often do what?
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Answer A: Need a longer distance to stop because traction is poor
Stiff suspension and little weight over the tires reduce grip, so the wheels lock early and the vehicle can take longer to stop.
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27. What does the working load limit stamped on a chain or strap describe?
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Answer B: The maximum load the device is rated to hold in normal use
The working load limit is the rated safe capacity for everyday use, deliberately set well below the force that would break the device.
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28. A load overhangs the rear of the trailer. What must the driver check before leaving?
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Answer D: That the overhang is marked as required, with flags or lamps as conditions demand
A projecting load has to be made visible to other drivers, with flags in daylight and lamps when lights are required, so nobody runs into what they cannot see.
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29. What must the driver confirm about the required emergency equipment before a trip?
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Answer A: That it is in place, in working order and ready to be used
Federal rules require the driver to be satisfied that the emergency equipment is present and ready, because it is needed at the worst possible moment.
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30. How should a driver use brakes fitted with an antilock system during an emergency stop?
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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.
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31. After two hours of driving you measure a tire and the pressure reads higher than the cold figure. What should you do?
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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.
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32. Who may remove an out-of-service sticker from a commercial vehicle?
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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.
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33. What should you look for on the electrical wiring in the engine compartment?
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Answer A: Worn, frayed or cracked insulation and loose or corroded connections
Damaged insulation can short a circuit against the frame or engine, which can kill a lamp you depend on or start a fire.
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34. You need to pull off onto the shoulder because of a problem with the load. How should you communicate that to other drivers?
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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.
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35. Your speedometer stops working during the pre-trip check. How should it be treated?
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Answer D: As a defect, because the driver cannot judge and control speed without it
A working speedometer is required equipment, because judging speed by feel in a heavy vehicle is unreliable and speed governs stopping distance.
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36. Under federal rules, what is required of a commercial driver who wants to use a mobile phone while driving?
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Answer B: The phone must be hands-free and started with no more than a single button press, and it must not be held
Federal rules ban texting and hand-held phone use while driving a commercial vehicle; reaching for, holding or dialing a phone is a violation.
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37. A driver snores heavily, stops breathing briefly during the night and is tired all day despite long hours in bed. What should be suspected?
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Answer B: Sleep apnea
Sleep apnea repeatedly interrupts breathing during sleep, so the driver never gets true rest and stays dangerously drowsy during the day.
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38. What is normally required in order to move an over-width or over-length load?
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Answer B: A special permit along with warning devices such as flags and signs
Oversize movements need a permit plus marking devices, and travel is often limited to certain hours or routes.
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39. Cargo falls from your trailer and causes a crash behind you. Who is likely to answer for it?
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Answer C: The driver and the carrier, since securing the load on the road is their duty
Whoever loaded the vehicle, the driver and the carrier are responsible for the load being secure while it is on the road.
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40. You must steer hard around an obstacle at highway speed. What is the correct technique?
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Answer B: Avoid braking while turning, turn only as far as needed, and countersteer as soon as the obstacle is passed
Braking during a hard steering input can lock the wheels and start a skid, and turning back at once keeps the vehicle from running off the far side of the road.
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41. Regular mirror checks during a long trip can reveal which developing problem?
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Answer D: Smoke coming from a tire or from a wheel
Overheating tires, wheel bearings and brakes usually show as smoke long before anything appears on the dash, and mirrors are where a driver sees it.
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42. You have countersteered to correct a rear-wheel skid and the vehicle straightens out. What must you be ready for next?
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Answer D: The vehicle may swing back the other way, so you must steer again to correct it
A vehicle coming out of a skid tends to overshoot and swing in the opposite direction, and the driver must be ready to countersteer a second time.
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43. What must be true of the person who performs the annual periodic inspection?
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Answer D: They must meet the federal qualification requirements for an inspector
The inspection has to be done by someone who meets the federal training and experience requirements for inspectors, whoever employs them.
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44. Why do worn tires lose grip so quickly on a wet road?
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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.
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45. You normally pull an empty trailer, but today the same tractor is loaded to its legal maximum. What changes about getting under way?
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Answer A: You may need to start in a lower gear, since the load takes more pulling power
The heavier the load, the lower the gear needed to get the vehicle rolling without lugging or stalling the engine.
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46. During a stop you find a package in the trailer leaking an unknown chemical. What should you do?
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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.
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47. Within total stopping distance, what exactly is perception distance?
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Answer D: The distance traveled from the moment your eyes see a hazard until your brain identifies it
Perception distance covers only the time between seeing a hazard and recognizing it as a hazard, before any physical reaction begins.
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48. At the end of the day you find no defects on a property carrying vehicle. What does the federal rule require?
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Answer B: No written report is required, although the carrier may still ask for one
For property carrying vehicles the report is required only when a defect or deficiency is found or reported, although a carrier may impose a stricter policy.
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49. What is the purpose of the torque rods or radius rods you check on the suspension?
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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.
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50. A car is following you far too closely. What is the safest response?
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Answer A: Open up more space ahead so you can slow gradually, avoid sudden changes, and do not speed up
Extra room in front lets you slow smoothly instead of braking hard, which is exactly what the driver behind cannot cope with.