25 realistic Tank Vehicles practice questions for Washington CDL applicants. Required for: Vehicles with liquid or gaseous tanks ≥1,000 gallons. Official test: 20 questions, 16 correct to pass.
Question 1 of 25 · Tank Types
What is the purpose of internal baffles?
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A.
To reduce side-to-side surge
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B.
To reduce forward and back surge
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C.
To prevent leaks
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D.
To increase tank size
Correct answer: B.
Baffles reduce front-to-back surge but do not stop side-to-side surge.
Question 2 of 25 · Vehicle Dynamics
What can cause a tanker to roll over?
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A.
Sharp turns
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B.
Sudden steering corrections
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C.
Speed too high for road conditions
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D.
All of the above
Correct answer: D.
All of these can cause rollovers; smooth, slow inputs reduce risk.
Question 3 of 25 · Vehicle Dynamics
How can drivers prevent tanker rollover?
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A.
Reduce speed in curves and ramps
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B.
Avoid sudden steering
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C.
Maintain proper load and securement
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D.
All of the above
Correct answer: D.
Slow speed, smooth steering, and proper loading all help prevent rollovers.
Question 4 of 25 · Tank Types
What is a baffled tank?
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A.
A tank with internal walls that have holes to slow surge
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B.
A tank with separate compartments
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C.
A tank with a smooth interior
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D.
A tank with no walls inside
Correct answer: A.
Baffles slow forward and back surge, but not side-to-side surge.
Question 5 of 25 · Parking
What's the safest place to park a tank vehicle overnight?
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A.
Designated truck parking areas away from buildings
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B.
On the highway shoulder
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C.
In residential areas
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D.
Anywhere with lighting
Correct answer: A.
Use designated truck parking areas away from people and buildings.
Question 6 of 25 · Vehicle Dynamics
How do drivers minimize side-to-side surge?
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A.
Avoid abrupt lane changes and turns
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B.
Take turns wide and slow
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C.
Use partial loads
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D.
Both A and B
Correct answer: D.
Smooth, slow inputs and wide turns help reduce side-to-side surge.
Question 7 of 25 · Vehicle Dynamics
Why is liquid surge dangerous?
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A.
It can cause the truck to roll over
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B.
It can push the truck in the direction the wave moves
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C.
It can affect handling and braking
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D.
All of the above
Correct answer: D.
Surge can roll, push, and disrupt braking — drivers must anticipate it.
Question 8 of 25 · Rail Crossings
What's the recommended safe practice when crossing railroad tracks with a tanker?
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A.
Stop within 15-50 feet of nearest rail and look and listen for trains
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B.
Speed up across the tracks
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C.
Stop on the tracks
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D.
Drive across normally
Correct answer: A.
Stop 15 to 50 feet from nearest rail. Don't shift gears while crossing.
Question 9 of 25 · Tank Types
What's a key difference between compartmented and smooth-bore tanks?
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A.
Compartmented tanks reduce surge between sections
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B.
Smooth-bore tanks have less surge
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C.
They are the same in terms of surge
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D.
Compartmented tanks are always larger
Correct answer: A.
Compartmented tanks reduce overall surge by limiting movement to each section.
Question 10 of 25 · Mountain Driving
How do drivers control speed on downgrades with tankers?
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A.
Use lower gears and engine braking
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B.
Use service brakes only
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C.
Coast with no brakes
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D.
Use parking brake
Correct answer: A.
Use proper low gears and engine braking; service brakes only intermittently.
Question 11 of 25 · Backing
What should a driver do before backing a tanker?
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A.
Check the path with a helper
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B.
Look behind the vehicle
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C.
Walk around the vehicle to check clearances
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D.
All of the above
Correct answer: D.
Use a helper, walk-around, and check the path before backing.
Question 12 of 25 · Vehicle Dynamics
What's the most important thing to remember about driving a tanker?
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A.
Be aware of liquid surge and high center of gravity
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B.
Drive faster to maintain schedule
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C.
Skip pre-trip inspections
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D.
Ignore weather conditions
Correct answer: A.
Surge and CG awareness are the cornerstones of safe tanker driving.
Question 13 of 25 · Vehicle Dynamics
How does liquid weight affect handling?
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A.
It changes the center of gravity
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B.
It affects acceleration
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C.
It affects braking
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D.
All of the above
Correct answer: D.
Liquid loads alter CG and dramatically affect acceleration and braking.
Question 14 of 25 · Emergency Equipment
What equipment must be on a HazMat tank vehicle?
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A.
Emergency response equipment
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B.
Spill kits as required
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C.
Communication devices
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D.
All of the above
Correct answer: D.
Carry spill response gear, communication, and any other required equipment.
Question 15 of 25 · Vehicle Dynamics
When is it most dangerous to brake suddenly in a tanker?
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A.
When tank is partially full
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B.
When tank is fully loaded
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C.
When tank is empty
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D.
When tank is heated
Correct answer: A.
Partial loads create the most surge during sudden braking.
Question 16 of 25 · Loading
Why must tanker drivers be careful when refueling?
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A.
Risk of fire from spills
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B.
Risk of cargo contamination
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C.
Risk of overloading
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D.
Both A and B
Correct answer: D.
Spills can ignite and cargo can be contaminated by fuel.
Question 17 of 25 · Loading
What's the consequence of overloading a tank?
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A.
Increased wear on tires and brakes
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B.
Possible tank rupture
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C.
Illegal weight violations
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D.
All of the above
Correct answer: D.
Overloading causes wear, legal trouble, and danger of tank failure.
Question 18 of 25 · Emergencies
What action should a driver take if a tank starts to leak?
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A.
Stop immediately in a safe area and report the leak
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B.
Continue to destination
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C.
Try to close the leak
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D.
Drive faster
Correct answer: A.
Stop in a safe area, secure the area, and notify the carrier and emergency services.
Question 19 of 25 · Vehicle Dynamics
Why must drivers be especially careful when starting and stopping a tanker?
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A.
Surge can cause loss of control
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B.
Engine torque is too high
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C.
Brakes are weaker
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D.
Steering is harder
Correct answer: A.
Surge during starts and stops can shove the vehicle and cause loss of control.
Question 20 of 25 · CDL Rules
How are tanker drivers trained for hazardous cargo?
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A.
Same as regular drivers
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B.
They receive specialized training and may need HazMat endorsement
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C.
No specific training required
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D.
They are trained by the shipper
Correct answer: B.
Hazardous tankers require additional training and often a HazMat endorsement.
Question 21 of 25 · Adverse Conditions
What's the safe way to handle a tanker on icy roads?
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A.
Slow down and increase following distance
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B.
Use chains if required
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C.
Avoid sudden braking and steering
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D.
All of the above
Correct answer: D.
Reduced speed, chains where required, and smooth inputs reduce risk on ice.
Question 22 of 25 · Placards
What's the role of the tanker placard?
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A.
To identify cargo for emergency responders
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B.
To indicate the vehicle is heavy
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C.
To indicate the vehicle is restricted
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D.
To warn of slow speed
Correct answer: A.
Placards identify cargo, alerting first responders to the type of hazard.
Question 23 of 25 · Speed Management
When should tank drivers especially reduce speed?
-
A.
On wet or slippery roads
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B.
On curves
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C.
On ramps
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D.
All of the above
Correct answer: D.
Slow down on wet roads, curves, and ramps — all increase rollover risk.
Question 24 of 25 · Speed Management
What should you do when going around curves with a tanker?
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A.
Slow down well below the posted speed
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B.
Drive at the posted speed limit
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C.
Use the engine retarder
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D.
Lock the brakes
Correct answer: A.
Take curves at speeds well below the posted limit to avoid rollovers.
Question 25 of 25 · Inspection
What is the proper way to inspect a tank before driving?
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A.
Check valves, manhole, and tank shell for leaks and damage
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B.
Just check the tires
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C.
Only inspect the engine
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D.
Skip inspection if you're in a hurry
Correct answer: A.
Inspect valves, manhole, shell, hoses, and other tank components every pre-trip.
About the Tank Vehicles Test
The Tank Vehicles test covers inspecting tank vehicles, driving tank vehicles, surge and liquid movement, baffled and unbaffled tanks, outage, and safe driving rules unique to large liquid loads. Tank vehicles handle very differently from dry-freight vehicles because liquid surge can shove the vehicle in the direction the wave moves.
The Washington Department of Licensing administers this knowledge test as part of its commercial driver license program. To earn the Tank Endorsement (N) on your Washington CDL, you need to score at least 16 out of 20 on the official version.
Topics covered on this practice test
- Vehicle Dynamics: 8 questions
- Tank Types: 3 questions
- Loading: 2 questions
- Speed Management: 2 questions
- Parking: 1 question
- Rail Crossings: 1 question
- Mountain Driving: 1 question
- Backing: 1 question
- Emergency Equipment: 1 question
- Emergencies: 1 question
- CDL Rules: 1 question
- Adverse Conditions: 1 question
- Placards: 1 question
- Inspection: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for Washington until you're ready for the official exam.
Tips specific to the Tank Vehicles test
Tank vehicle questions focus on liquid surge, outage, smooth-bore versus baffled tanks, high center of gravity, and the special braking and turning techniques required to keep a partially-loaded tank under control. Expect several questions about leak response and load distribution.