Oregon DMV CDL General Knowledge Practice Test 3
Test 3 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 Oregon test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?
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Answer C: After 8 cumulative hours of driving time
Driving is not allowed after 8 cumulative hours of driving time without at least a 30 consecutive minute interruption of driving.
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2. May a commercial driver use a hand-held phone while stopped at a red light?
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Answer B: No, a stop in traffic still counts as driving
Hand-held use is allowed only when the vehicle has been moved to the side of or off the highway and halted where it can safely remain stopped.
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3. A strap is a little too long, so a driver ties a knot in it to take up the slack. Is that acceptable?
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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.
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4. 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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5. What is the correct way to make a normal stop?
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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.
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6. A carrier operates commercial vehicles every day of the week. What weekly on-duty limit applies to its drivers?
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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.
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7. Within what distance should high beams be lowered at night?
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Answer D: Within about 500 feet of an oncoming vehicle and within about 500 feet of a vehicle you are following
High beams blind other drivers at close range, so they are lowered at roughly the same distance whether the other vehicle is coming toward you or is ahead of you.
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8. On a one way street or a divided highway, where are the warning devices placed?
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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.
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9. What must be true of the trailer landing gear before you move off?
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Answer B: Fully raised, with the crank handle secured and no missing or damaged parts
Landing gear left part way down can strike a railway crossing or a ramp, and a loose crank handle can swing out into a passing vehicle.
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10. A tire may be regrooved only when what is true?
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Answer B: It carries a marking from the manufacturer showing that it is regroovable
Only casings built with extra rubber under the tread and marked regroovable by the manufacturer may be cut, because others would be grooved into the belts.
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11. What is the minimum age to drive a commercial motor vehicle in interstate commerce from Oregon?
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Answer D: 21 years
Oregon applies the federal rule requiring a commercial driver to be at least 21 years old for interstate commerce, while intrastate driving is allowed from 18.
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12. When speed doubles, what happens to braking distance?
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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.
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13. A hazard suddenly appears ahead and you must act. Which is usually the faster way to avoid it in a heavy vehicle?
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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.
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14. What happens when too much of the load sits over the steering axle?
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Answer D: The vehicle becomes hard to steer and the axle and its tires can be damaged
Weight beyond the front axle rating makes the steering heavy and can overload the axle and the tires carrying it.
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15. As a long vehicle goes around a corner, how do the rear wheels travel compared with the front wheels?
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Answer A: They follow a tighter path, closer to the inside of the turn
The rear wheels off-track toward the inside of the turn, and the longer the vehicle the bigger the difference, which is why the front must swing wide enough to keep the rear off the curb.
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16. What actually lowers the amount of alcohol in the bloodstream?
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Answer B: Time
The liver removes alcohol at a fixed rate, so nothing but the passage of time reduces blood alcohol concentration.
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17. What can repeated violations of the federal phone and texting rules cost a commercial driver?
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Answer D: Disqualification of the commercial driver license
Multiple convictions for using a hand-held phone or texting while driving a commercial vehicle lead to disqualification, on top of fines for driver and carrier.
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18. How does Oregon's CDL manual define use of a hand-held mobile telephone for a CMV driver?
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Answer B: Using at least one hand to hold a mobile telephone to conduct a call
Oregon's CDL manual defines using a hand-held mobile telephone as using at least one hand to hold the device to conduct a voice communication.
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19. What does the suspension system weight rating tell the driver?
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Answer A: The maximum weight that the manufacturer says the suspension can carry
Like tires and axles, suspensions have a manufacturer capacity, and loading beyond it can damage springs and air bags.
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20. 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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21. What should the ammeter or voltmeter show once the engine is running?
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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.
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22. Which document must be available to show that the annual inspection was carried out?
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Answer C: The inspection report or a copy of it, or a decal displayed on the vehicle
Proof of the periodic inspection travels with the vehicle, either as the report itself or as the decal fixed where an inspector can see it.
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23. A driver hauling a sealed trailer that cannot be opened is still responsible for what?
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Answer D: Making sure the rig is not over the gross or axle weight limits
A seal prevents inspecting the contents, but the driver must still confirm the vehicle is not overloaded.
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24. How do you get more engine braking from an automatic transmission on a downgrade?
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Answer B: Select a lower range before starting down
Locking the transmission into a lower range keeps engine speed high enough to hold the vehicle back and spares the service brakes.
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25. What is generally the safest speed in dense but freely moving highway traffic?
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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.
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26. Why must tiedowns be rechecked during a trip even when they were tight at the start?
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Answer C: Road vibration and cargo movement can loosen them as the miles go by
Straps and chains settle and loosen as the vehicle bounces and the cargo shifts slightly, so the load must be rechecked at the required intervals.
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27. Experienced commercial drivers scan the road ahead by roughly how much travel time?
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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.
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28. 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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29. 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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30. After starting the engine, how quickly should the oil pressure gauge come up to its normal range?
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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.
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31. You are about to back across a quiet street into a driveway. Which of these is good practice before you start to move?
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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.
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32. You are backing into a yard where electrical wires cross overhead. What is the main concern?
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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.
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33. 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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34. On the Interstate System, what are the federal maximums for a tandem axle group and for gross vehicle weight?
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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.
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35. Why does a driver use pull-ups while backing into a tight space?
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Answer C: To pull forward and start the approach again when the angle is going wrong
Stopping, pulling ahead and repositioning fixes a bad angle safely, and there is nothing wrong with needing more than one attempt.
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36. What are you checking when you look at the batteries during the engine compartment inspection?
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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.
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37. What condition should the fifth wheel be in before you back under a trailer?
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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.
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38. Which combination of warning devices meets the requirement for a stopped commercial vehicle?
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Answer A: Three reflective triangles, or six fusees, or three liquid burning flares
A vehicle may carry three bidirectional reflective triangles, six fusees or three liquid burning flares as its warning devices.
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39. How long must an Oregon commercial learner permit be held before the CDL skills test?
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Answer B: 14 days
Oregon requires the commercial learner permit to be held for at least 14 days before the applicant can take the CDL skills test.
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40. Where are the OVERSIZE LOAD signs normally carried on a vehicle moving under such a permit?
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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.
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41. How does Oregon's CDL manual define texting for a commercial motor vehicle driver?
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Answer C: Manually entering text into, or reading text from, a device
Oregon's CDL manual defines texting broadly as manually entering text into, or reading text from, a phone, computer, or other device used to enter, write, send, receive, or read text.
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42. An automatic transmission is left in its normal drive position as the vehicle rolls down a long grade. What does it tend to do?
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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.
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43. At a rest area you find that the load has shifted although the straps still feel tight. What should you do?
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Answer C: Correct the load before driving on, since a shifted load is no longer secure
Movement means the securement has already failed once, and a load that has shifted can shift again, so it is put right before the vehicle moves.
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44. What is the minimum tread depth required in every major groove of a steering axle tire?
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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.
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45. You are backing a tractor-trailer in a straight line and the trailer starts to drift to the left. What is the standard correction?
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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.
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46. You are dropping a loaded trailer in a yard. How far should the landing gear be lowered?
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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.
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47. A CDL holder's first railroad-highway grade crossing violation in Oregon, such as failing to stop when required, results in disqualification for how long?
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Answer B: At least 60 days
Oregon's Commercial Driver Manual sets a 60-day disqualification for a first railroad-highway grade crossing violation, rising to 120 days for a second violation and 1 year for a third violation within three years.
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48. With the tractor coupled to the trailer, what should you see between the upper and lower fifth wheel plates?
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Answer A: No space at all between the two plates
Any daylight between the plates means the trailer is not properly seated on the fifth wheel and the coupling can come apart under load.
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49. Under federal rules, which commercial vehicles must stop at every railroad crossing before proceeding?
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Answer D: Passenger buses and placarded hazardous materials vehicles
Buses carrying passengers and vehicles required to display hazardous materials placards must stop at crossings, while other commercial vehicles slow and check.
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50. At the scale your tractor drive axles are overweight while the trailer axles have room. Sliding the trailer tandems forward will do what?
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Answer C: Move weight off the drive axles and onto the trailer axles
Sliding the trailer tandems forward brings the rear support closer to the load, so the trailer axles pick up more weight and the drive axles carry less; sliding them rearward does the opposite.