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Washington General Knowledge CDL Practice Test

Below are 25 exam-style questions for the Washington General Knowledge CDL knowledge test, modeled on the FMCSA-aligned content used by the Washington State Department of Licensing. 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
Which is true about driving in fog?
  • A Use high-beam headlights for maximum visibility
  • B Use the four-ways while in motion at highway speed
  • C Use low-beam headlights and slow down
  • D Drive faster to get out of the fog quickly
Correct answer: C
High beams reflect off fog and reduce visibility. Slow down and use low beams or fog lamps if equipped.
Question 2 of 25
When backing a heavy vehicle, you should:
  • A Back fast to get it over with
  • B Back to the right whenever possible
  • C Use a helper and walk around the vehicle first
  • D Back without using mirrors so you can watch out the window
Correct answer: C
Always GOAL — Get Out And Look — and use a helper. Backing to the left when possible is preferred because you can see better, not to the right.
Question 3 of 25
Acceleration must be smooth and gradual to avoid:
  • A Engine damage
  • B Wasting fuel only
  • C Annoying passengers
  • D Powertrain wear and possible loss of control on slippery surfaces
Correct answer: D
Quick throttle inputs on slick surfaces can spin the drive wheels and cause a tractor jackknife. Smooth acceleration avoids this and reduces wear.
Question 4 of 25
A "wig-wag" is:
  • A A fuel-saving switch
  • B A type of cargo strap
  • C A trailer hitch component
  • D A low-air pressure warning device that drops a flag in front of the driver
Correct answer: D
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 5 of 25
A driver's blood-alcohol concentration (BAC) of 0.04% or higher while operating a commercial motor vehicle is:
  • A Considered driving under the influence for CDL purposes
  • B Allowed if the driver feels fine
  • C A traffic violation, but not a CDL disqualification
  • D Allowed off-duty only
Correct answer: A
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 6 of 25
You are driving a heavy vehicle and have to stop on a long downgrade. Which is the safest way?
  • A Pump the brakes hard and fast
  • B Use a low gear and steady moderate brake application
  • C Disengage the clutch and coast
  • D Use the parking brake to slow down
Correct answer: B
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 7 of 25
A driver who has lost the ability to safely brake the vehicle on a downgrade should:
  • A Use the parking brake hard
  • B Coast in neutral
  • C Shift into reverse
  • D Look for an escape ramp
Correct answer: D
Long downgrades have escape ramps for runaway trucks. Use them. Coasting in neutral is illegal in many states and worsens the problem.
Question 8 of 25
A driver must report any accident involving a CMV to the carrier within:
  • A A reasonable time, before going off duty
  • B 7 days
  • C 1 hour
  • D 24 hours
Correct answer: A
FMCSA rules require notification of the motor carrier in a reasonable time — most policies treat that as before going off duty.
Question 9 of 25
Skids are most often caused by:
  • A Properly working brakes
  • B Old tires
  • C Driving too fast for conditions
  • D Manual transmissions
Correct answer: C
The dominant cause of skids identified by the FMCSA is driving too fast for the road or weather. Sudden steering, hard braking, or hard acceleration usually triggers them.
Question 10 of 25
On a long downgrade, why is it dangerous to use the brakes too much?
  • A It wastes brake pads
  • B Brake fade can leave you with reduced or no braking power
  • C It triggers the ABS warning light
  • D It cools the brakes too much
Correct answer: B
Heat from continuous braking causes the friction surfaces to lose their grip. Use a low gear and brief, moderate brake applications.
Question 11 of 25
When approaching a steep downgrade, the basic safe-driving rule is:
  • A Coast in neutral
  • B Use the parking brake intermittently
  • C Stay in high gear
  • D Select a lower gear before starting down
Correct answer: D
Get into a low gear before the descent so the engine helps hold the vehicle back.
Question 12 of 25
How does ABS help in an emergency stop?
  • A It increases brake pressure automatically
  • B It prevents wheel lockup so the driver can keep steering
  • C It applies the parking brake
  • D It always stops the vehicle in a shorter distance
Correct answer: B
ABS keeps the wheels rolling so steering control is preserved. It is not a shorter-distance device.
Question 13 of 25
A controlled braking technique means:
  • A Coasting in neutral
  • B Locking the wheels
  • C Applying the brakes as hard as possible without locking the wheels
  • D Pumping the brakes hard and fast
Correct answer: C
Controlled braking applies brakes hard but stops short of wheel lock-up. With ABS, you can simply press and hold full pressure.
Question 14 of 25
When you are being tailgated, you should:
  • A Brake suddenly to teach a lesson
  • B Speed up to get away
  • C Increase your following distance from the vehicle in front to give both of you more room
  • D Move to the left lane only
Correct answer: C
Adding cushion ahead gives the tailgater room to pass safely and reduces the chance of a chain rear-end collision.
Question 15 of 25
When approaching a railroad crossing in a CMV that is not required to stop, you should:
  • A Cross at maximum speed to get over quickly
  • B Slow down, look, listen, and be prepared to stop
  • C Honk and proceed
  • D Always come to a full stop regardless of traffic
Correct answer: B
Even when not required by class to stop, you must always be prepared to stop. Buses, hazmat, and certain other vehicles must stop every time.
Question 16 of 25
Which of the following is a valid reason to refuse a load?
  • A It would push your weight over legal limits
  • B It would make you exceed federal hours-of-service rules
  • C All of the above
  • D The cargo is not properly secured or placarded
Correct answer: C
A driver is required by federal law to refuse loads that violate HOS, weight, or hazmat rules. The driver, not the dispatcher, is liable.
Question 17 of 25
When approaching a curve, you should:
  • A Downshift in the curve
  • B Stay at the same speed
  • C Slow down before entering and accelerate gently through it
  • D Brake while in the curve
Correct answer: C
Speed should already be set before the curve. Braking or downshifting in a curve can upset the vehicle's balance.
Question 18 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 19 of 25
The most important hand position on the steering wheel is:
  • A 12 and 6
  • B Both hands at the bottom
  • 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 20 of 25
A CDL is required to operate a single vehicle with a GVWR of:
  • A 20,000 lbs or more
  • B 10,001 lbs or more
  • C 26,001 lbs or more
  • D 40,000 lbs or more
Correct answer: C
Single vehicles at or above 26,001 lbs GVWR (Class B) require a CDL. Class A applies to combinations at or above 26,001 lbs GCWR with a trailer over 10,000 lbs.
Question 21 of 25
Black ice is most likely on:
  • A Gravel surfaces
  • B Roads in direct sunlight
  • C Concrete pavement only
  • D Bridges and overpasses
Correct answer: D
Bridges and overpasses freeze first because cold air circulates above and below them. They are the most-asked test scenario for sudden ice.
Question 22 of 25
When should you use four-way flashers?
  • A When you are stopped or moving slowly enough to be a hazard
  • B Only on the highway
  • C Whenever you feel like it
  • D Only at night
Correct answer: A
Four-ways are for vehicles stopped on or near the road or moving so slowly that they are a hazard.
Question 23 of 25
Drivers may not drive after being on duty:
  • A 14 consecutive hours since coming on duty
  • B 15 hours of driving
  • C 8 hours in any 24-hour period
  • D 20 hours in a 24-hour period
Correct answer: A
The 14-hour rule limits the on-duty window during which up to 11 hours of driving may occur.
Question 24 of 25
Which of the following is NOT part of a pre-trip inspection?
  • A Adjusting the trailer brakes individually
  • B Walking around the vehicle and checking lights
  • C Checking the engine compartment
  • D Testing the service and parking brakes
Correct answer: A
Adjusting brakes is a maintenance task done by qualified personnel, not a pre-trip step. The driver checks for proper operation, not adjustment.
Question 25 of 25
Hydroplaning is most likely when:
  • A Roads are dry but hot
  • B Tires lose contact with the road on a film of water
  • C You brake hard on dry pavement
  • D Tires are over-inflated
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.

Study tips for the Washington General Knowledge exam

The General Knowledge portion of the Washington CDL exam is graded out of the bank of questions the Washington State Department of Licensing draws from each year. While the exact bank is not published, every question is sourced from the General Knowledge chapter of the Washington 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 Washington 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 Washington State Department of Licensing 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 Washington 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 Washington 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 Washington State Department of Licensing office.

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

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