Oregon General Knowledge CDL Practice Test

This is a free 20-question practice test for the General Knowledge portion of the Oregon Commercial Driver's License knowledge exam. Questions are pulled from a pool of 97 drawn from the AAMVA CDL Manual, which is the source document the Oregon Driver and Motor Vehicle Services uses to write its actual exam.

How it works: Click an answer. The correct choice highlights in green, and you'll see a short explanation. Aim for 85% or better before you sit for the real test in Oregon.

Question 1 of 20

Federal regulations require a tie-down for every cargo, with a minimum of:

One tie-down for any cargo
One tie-down for items less than 5 feet long, two for items 5+ feet
At least one tie-down for each 10 feet of cargo, with minimums depending on length and weight
Tie-downs are not required for closed trailers

Correct. The general rule: at least one tie-down per 10 feet of article, plus a minimum based on length and weight (commonly two minimum for items over 5 feet or 1,100 lbs).

Question 2 of 20

You are driving on a two-lane road. An oncoming driver drifts into your lane. You should:

Steer right onto the shoulder
Flash your high beams
Honk your horn
Brake hard and stop in your lane

Correct. When an oncoming driver drifts into your lane, the safer escape is right onto the shoulder. Steering left risks a head-on if the other driver corrects.

Question 3 of 20

Hydroplaning is most likely to occur when:

Driving at low speed in light rain
Tires lose contact with the road and ride on water
Brakes are applied gently
Tires are over-inflated

Correct. Hydroplaning occurs when a film of water comes between the tires and the road, causing the tires to lose contact with the pavement. Higher speeds, worn tires, and standing water increase the risk.

Question 4 of 20

Most drivers who fall asleep at the wheel:

Are aware they are tired and pull over
Do not realize they are about to fall asleep
Have been drinking
Have been on the road less than an hour

Correct. Most drivers who fall asleep do not realize how drowsy they are. The only fix is to stop and rest before fatigue reaches that point.

Question 5 of 20

How can you tell if you are driving in mountains?

You see deer
Your engine works harder on grades, both up and down
Roads are paved
It is colder

Correct. Mountain driving demands attention to grade-related challenges: gear selection on upgrades, speed control on downgrades, escape ramp awareness.

Question 6 of 20

When approaching a downgrade, you should select:

A higher gear than you would for an upgrade
A lower gear before starting down, never after
Neutral, and let gravity slow you
Whatever gear you are in

Correct. Select your gear before the downgrade — modern transmissions can be hard or impossible to shift into a lower gear once you are descending and engine RPM has dropped.

Question 7 of 20

A vehicle's "no zone":

Refers to the lane next to the cab
Includes the front, sides, and rear blind spots where other vehicles disappear from view
Is the area in front of the truck only
Does not exist for cars

Correct. The "no zone" is the set of blind spots around a truck — front, both sides (especially right), and rear — where other vehicles cannot be seen.

Question 8 of 20

A driver convicted of driving a CMV with a BAC of .04 or higher faces:

No penalty
A warning
Disqualification of at least one year for the first offense
License renewal

Correct. A first conviction of driving a CMV with BAC ≥ .04 disqualifies the driver for at least one year (three years if hauling hazmat).

Question 9 of 20

Which is the safest stopping technique for a non-ABS vehicle whose brakes have started to lock up?

Continue braking hard until you stop
Stab braking: brake hard, release, brake hard again
Pump the brakes lightly
Coast in neutral

Correct. On a non-ABS vehicle, stab braking — full brake application until wheels lock, release, repeat — keeps the vehicle straight while still slowing.

Question 10 of 20

What is the minimum tread depth required for the front (steering) tires of a commercial vehicle?

1/32 inch
2/32 inch
4/32 inch
6/32 inch

Correct. Steer-axle tires must have at least 4/32-inch tread depth in every major groove. Other tires require at least 2/32 inch.

Question 11 of 20

If your vehicle hydroplanes, what should you do?

Brake hard immediately
Steer sharply to recover
Release the accelerator and push in the clutch
Accelerate to push through

Correct. Release the accelerator and push in the clutch. Do not brake or steer hard until the tires regain contact.

Question 12 of 20

A driver may resume driving after a 10-hour off-duty period only if:

They have not exceeded the on-duty hour limits and are not impaired
They feel rested
They have eaten
They have refueled

Correct. HOS rules limit driving and on-duty hours within a fixed window. After 10 hours off-duty, driving may resume only if other limits also allow.

Question 13 of 20

Which of the following is true about the front-end shock absorbers?

They have nothing to do with handling
Worn shock absorbers can cause poor handling and uneven tire wear
They are part of the brake system
They affect only ride comfort, never safety

Correct. Shock absorbers control suspension oscillation. Worn shocks contribute to poor handling, uneven tire wear, and reduced control on rough roads.

Question 14 of 20

Which of the following is true about driving at night?

Headlights illuminate further than you can stop within
You should drive faster to keep up with traffic
You should drive at a speed that lets you stop within the distance illuminated by your headlights
You can rely on oncoming headlights to help you see

Correct. Drive at a speed where your stopping distance does not exceed the distance you can see — typically 250 feet on low beams, 350-500 feet on high beams.

Question 15 of 20

What is the minimum amount of tread depth required on tires other than front (steering) tires?

1/32 inch
2/32 inch
4/32 inch
5/32 inch

Correct. Non-steer tires must have at least 2/32-inch tread depth in every major groove.

Question 16 of 20

On a tight curve in a rural mountain road:

Approach at posted speed
Slow down before entering the curve, take a wider line if you can do so safely
Speed up
Stay on the centerline

Correct. Mountain curves often have advisory speeds well below your safe load speed. Slow before entering and use the full lane safely.

Question 17 of 20

You are driving in a work zone. You should:

Drive faster to clear the zone
Slow down, increase following distance, watch for workers
Use the shoulder
Honk repeatedly

Correct. Work-zone fines double or more in most states. Slow down, give the vehicle ahead extra space, watch for workers and equipment, and follow signed speed reductions.

Question 18 of 20

A "convex mirror" on the side of a tractor:

Provides a wider view, but objects appear smaller and farther away than they really are
Magnifies objects
Has a flat reflection
Cannot be used in daylight

Correct. Convex (curved) mirrors widen the field of view but distort distance perception — objects look smaller and farther than they actually are.

Question 19 of 20

Which of these vehicles is most likely to have to stop at a railroad crossing?

A school bus or a placarded hazmat vehicle
A pickup truck
A motorcycle
A passenger car

Correct. Buses, school buses, and placarded hazmat vehicles must stop at every railroad crossing 15 to 50 feet from the nearest rail.

Question 20 of 20

You are about to drive a vehicle that you have not driven before. What should you do?

Get in and drive — every commercial vehicle handles the same
Inspect the vehicle to make sure it is safe and the cargo is properly secured
Drive briefly without cargo to learn the controls
Skip the inspection if the previous driver inspected it

Correct. Federal regulations require the driver to be satisfied that the vehicle is in safe operating condition before driving. The previous driver's inspection does not relieve you of that responsibility.

About the Oregon General Knowledge exam

Most state DMVs administer 50 General Knowledge questions and require 80% (40 correct) to pass. Questions are pulled from a much larger pool, so two applicants taking the test on the same day will see different mixes. The questions on this site are drawn from the AAMVA CDL Manual chapters that every state's exam is built from.

The Oregon Driver and Motor Vehicle Services follows the federal CDL standards established by FMCSA. To earn the General Knowledge credential, you must answer at least 80% of the questions correctly. Many candidates score lower the first time because the test pulls from a large pool — refreshing this page will give you a different mix of questions, drawn from the same authoritative source.

Want more practice? Try the full General Knowledge question bank or browse all Oregon CDL practice tests.