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Oregon General Knowledge CDL Practice Test

Below are 25 exam-style questions for the Oregon General Knowledge CDL knowledge test, modeled on the FMCSA-aligned content used by the Oregon Driver and Motor Vehicle Services. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.

Heads up: this is a study tool, not a graded exam. Cover the answer with your hand or a sheet of paper for an honest practice run, then re-read the explanations for any questions you missed. Aim for 22 out of 25 or better, three times in a row, before scheduling the real exam.
Question 1 of 25
Cargo that hangs more than 4 feet beyond the back of the vehicle must be marked with:
  • A A green flag
  • B Yellow tape only
  • C Nothing — federal rules do not require marking
  • D A red flag (or red light at night) at the extreme rear
Correct answer: D
Federal rules require a red flag during the day and red lights at night for projecting cargo beyond 4 feet.
Question 2 of 25
When should you do an en-route inspection?
  • A At the end of the trip
  • B Only when the load is hazardous
  • C Within the first 25 miles, then about every 150 miles or every 3 hours
  • D Only if a warning light comes on
Correct answer: C
The FMCSA model manual recommends a check within the first 25 miles to catch loose cargo or under-inflated tires that have warmed up, then about every 150 miles or 3 hours, and any time you stop.
Question 3 of 25
What does it mean when a road sign says "Bridge formation may freeze before road"?
  • A The bridge is closed in winter
  • B The pavement under the bridge is reinforced
  • C Bridge surfaces freeze first because of air circulation underneath
  • D Bridges are inspected only in winter
Correct answer: C
Cold air around bridges and overpasses cools the deck more quickly than the surrounding road, which is why ice often appears there first.
Question 4 of 25
GCWR stands for:
  • A Gross Combination Weight Rating
  • B General Carrier Weight Rating
  • C Government Combination Weight Reading
  • D Gross Cargo Weight Rating
Correct answer: A
GCWR is the maximum allowable weight of a power unit plus a towed unit, including all cargo. It determines whether a license is Class A.
Question 5 of 25
You are driving on a two-lane road and you see a driver about to pull out from a side road. You should:
  • A Cover the brake and slow down
  • B Honk and accelerate
  • C Move to the right lane
  • D Maintain speed
Correct answer: A
Anticipate the worst-case behavior. Cover the brake — keeping your foot just over it — so you can react if they pull out.
Question 6 of 25
Hours-of-service records are required to be kept by:
  • A No one
  • B The carrier only
  • C The driver, in the form of a logbook or electronic logging device
  • D The dispatcher only
Correct answer: C
Drivers are responsible for accurate hours-of-service records, kept either on paper logs or, for most carriers, on an ELD.
Question 7 of 25
The maximum allowable on-duty driving time after 8 consecutive hours off duty is:
  • A 11 hours
  • B 16 hours
  • C 10 hours
  • D 14 hours
Correct answer: A
After 10 hours off duty, a property-carrying driver may drive up to 11 hours, within a 14-hour on-duty window.
Question 8 of 25
A vehicle's "no-zone" is:
  • A The fuel tank area
  • B The area in front of the steer axle
  • C The area immediately next to it where other drivers are hidden in your blind spots
  • D A federal speed restriction
Correct answer: C
No-zones are the four blind-spot areas (front, rear, and both sides) where smaller vehicles are difficult or impossible to see in your mirrors.
Question 9 of 25
Hydroplaning is most likely when:
  • A Tires are over-inflated
  • B Tires lose contact with the road on a film of water
  • C You brake hard on dry pavement
  • D Roads are dry but hot
Correct answer: B
Hydroplaning happens when tires ride on top of standing water at speed. Reduce risk by slowing down, keeping tires properly inflated and tread depth adequate.
Question 10 of 25
To recover from a front-wheel skid, you should:
  • A Accelerate
  • B Brake hard immediately
  • C Release the brake, let the wheels turn freely, and let the vehicle slow down
  • D Steer sharply in the opposite direction
Correct answer: C
A front-wheel skid is usually caused by braking too hard. Release the brake to allow the front tires to grip again so steering returns.
Question 11 of 25
The most important hand position on the steering wheel is:
  • A Both hands at the bottom
  • B 12 and 6
  • C One hand at 12
  • D 10 and 2 (or 9 and 3)
Correct answer: D
A balanced grip at 10-and-2 or 9-and-3 gives the most control. One-handed and bottom-of-wheel positions reduce reaction time.
Question 12 of 25
A leaking exhaust system is dangerous because:
  • A It is illegal
  • B It causes the engine to overheat
  • C It increases fuel use
  • D It can let poisonous carbon monoxide into the cab
Correct answer: D
Carbon monoxide from a leaking exhaust can cause headaches, drowsiness, and unconsciousness. The illegality is real but the safety risk is the bigger answer.
Question 13 of 25
The minimum tread depth for steer-axle tires is:
  • A 2/32 inch
  • B 4/32 inch
  • C 1/32 inch
  • D 6/32 inch
Correct answer: B
Steer tires must have at least 4/32 inch in every major groove. Other tires require at least 2/32 inch.
Question 14 of 25
You are driving a heavy vehicle and have to stop on a long downgrade. Which is the safest way?
  • A Use the parking brake to slow down
  • B Disengage the clutch and coast
  • C Pump the brakes hard and fast
  • D Use a low gear and steady moderate brake application
Correct answer: D
On a long downgrade, select a low gear before the descent and use steady, light to moderate braking. Hard pumping or coasting in neutral leads to brake fade and loss of control.
Question 15 of 25
A driver who refuses to take a required drug or alcohol test is treated as if they:
  • A Did not take the test, with no consequence
  • B Need to take it again later
  • C Took the test and passed
  • D Took the test and failed
Correct answer: D
Refusal is a federal CDL disqualification with the same consequences as a positive test.
Question 16 of 25
Stopping distance is made up of:
  • A Reaction distance only
  • B Brake-lag distance only
  • C Speed times weight
  • D Perception distance + reaction distance + brake-lag distance + braking distance
Correct answer: D
Total stopping distance has four parts. Air brakes add a brake-lag distance not present in hydraulic systems.
Question 17 of 25
Which is true about the use of turn signals?
  • A Signal only when other vehicles are present
  • B Signal early, signal continuously, and cancel after the turn
  • C Signal only at the moment you start turning
  • D Use the four-way flashers instead of signals at intersections
Correct answer: B
The federal model manual specifies signal early, continuously, and cancel after — the same three steps every state CDL test asks about.
Question 18 of 25
Which is required when stopping on the side of a level, straight, two-lane road?
  • A One reflective triangle within 10 feet
  • B A flare burning constantly
  • C A spotter walking 1,000 ft up the road
  • D Three reflective triangles: 10 ft, 100 ft, and 200 ft toward approaching traffic
Correct answer: D
On a level straight road, place triangles 10 feet behind the vehicle, 100 feet, and 200 feet to the rear in the direction of approaching traffic.
Question 19 of 25
When checking the engine compartment, you should make sure that:
  • A Engine oil level is safe to operate
  • B Coolant level is above LOW and the cap is secure
  • C Power steering fluid is at the proper level
  • D All of the above
Correct answer: D
A proper engine-compartment check covers oil, coolant, power steering fluid, windshield washer fluid, hoses, belts, and electrical wiring. Skipping any one of them defeats the purpose of the inspection.
Question 20 of 25
Which of the following is true about cargo securement?
  • A You must inspect cargo and securement before driving and within the first 50 miles
  • B Cargo is the shipper's responsibility, not yours
  • C Tying a load down once at the start is enough
  • D Federal rules do not apply to cargo securement
Correct answer: A
49 CFR Part 393 makes the driver responsible for inspecting cargo and its securement before driving and again within the first 50 miles, then every 150 miles or 3 hours.
Question 21 of 25
A driver convicted of a major offense (DUI, leaving the scene, etc.) in a CMV faces:
  • A No federal consequence
  • B A warning
  • C CDL disqualification for at least one year for a first offense
  • D A fine only
Correct answer: C
Major offenses carry a one-year CDL disqualification minimum (three years if hauling hazardous materials), and lifetime for a second.
Question 22 of 25
A driver's blood-alcohol concentration (BAC) of 0.04% or higher while operating a commercial motor vehicle is:
  • A Allowed if the driver feels fine
  • B Considered driving under the influence for CDL purposes
  • C Allowed off-duty only
  • D A traffic violation, but not a CDL disqualification
Correct answer: B
Federal rules treat 0.04% BAC in a CMV as DUI for CDL purposes — half the typical 0.08% limit for non-commercial drivers.
Question 23 of 25
A "wig-wag" is:
  • A A low-air pressure warning device that drops a flag in front of the driver
  • B A type of cargo strap
  • C A fuel-saving switch
  • D A trailer hitch component
Correct answer: A
On older trucks, a wig-wag is a mechanical low-air warning that lowers a flag into the driver's field of view when air pressure drops below safe limits.
Question 24 of 25
A Class C CDL is required to drive:
  • A Vehicles designed to carry 16+ passengers including the driver, or that require hazmat placards
  • B Any vehicle over 26,001 lbs
  • C Tractor-trailers under 26,001 lbs GCWR
  • D Class A combinations only
Correct answer: A
Class C covers vehicles that don't meet Class A or B but are designed to carry 16 or more passengers (including the driver) or carry placarded amounts of hazardous materials.
Question 25 of 25
Which is true about driving in rain?
  • A It is safe to drive at the posted speed limit
  • B Tire chains are required by federal law
  • C High beams improve visibility in heavy rain
  • D Roads are most slippery just after rain begins, when water mixes with road oil
Correct answer: D
The first few minutes of rain mix with oil and grime on the road and create the slipperiest conditions. Slow down and increase following distance.

Study tips for the Oregon General Knowledge exam

The General Knowledge portion of the Oregon CDL exam is graded out of the bank of questions the Oregon Driver and Motor Vehicle Services draws from each year. While the exact bank is not published, every question is sourced from the General Knowledge chapter of the Oregon CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.

Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official Oregon handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.

Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about General Knowledge.

Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The Oregon Driver and Motor Vehicle Services will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.

Finally, keep your General Knowledge fundamentals sharp even when you're focused on the General Knowledge exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh Oregon General Knowledge practice test before scheduling the real exam.

Next steps

Missed more than four questions? Re-read the General Knowledge study guide and the matching chapter in the official Oregon CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local Oregon Driver and Motor Vehicle Services office.

Already comfortable with this endorsement? Drill another: OR Air Brakes · OR Combination Vehicles · OR Hazardous Materials · OR Passenger · OR School Bus · OR Tank Vehicle · OR Doubles / Triples

New to the CDL process in Oregon? Read How to apply for a CDL in Oregon for the document checklist and step-by-step timeline.