Vermont Tanker CDL Practice Test

This is a free 20-question practice test for the Tanker portion of the Vermont Commercial Driver's License knowledge exam. Questions are pulled from a pool of 50 drawn from the AAMVA CDL Manual, which is the source document the Vermont Department of Motor Vehicles 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 Vermont.

Question 1 of 20

When the surge in a tanker pushes the rig forward at a stop, you may:

Brake harder
Be pushed past the intended stopping point
Skid backward
Have no effect

Correct. Forward surge can push the entire rig forward — past stop lines, into intersections, into the vehicle ahead. Plan your stops with extra distance.

Question 2 of 20

Tankers have a high center of gravity because:

The driver sits high
The load is in a tall, narrow tank
The cargo is light
The cab is wide

Correct. A tank carries its load high above the road. The center of gravity is much higher than for a flatbed of the same weight, increasing rollover risk.

Question 3 of 20

Tanker pre-trip should specifically check:

Tank shell, intake/discharge/cut-off valves, manhole covers, venting devices, and pressure-relief equipment
Only the tires
Only the engine
Only the placards

Correct. In addition to standard pre-trip, inspect the tank shell, all valves, manhole covers, vents, and pressure-relief devices.

Question 4 of 20

When driving a tanker, you should:

Drive faster on curves
Drive slower than posted curve speeds, especially on exit ramps
Use only the trailer brake
Match car speeds

Correct. Posted advisory speeds assume cars. A loaded tanker may roll over at the posted speed — slow well below posted speeds for ramps and curves.

Question 5 of 20

When braking a partially filled smooth-bore tank, you should:

Brake hard at the last minute
Brake gently and start braking earlier than usual to compensate for surge
Use only the trailer hand valve
Pump the brakes

Correct. In smooth-bore tanks, surge is severe. Brake gently and earlier than you would in a dry-van trailer to avoid being pushed forward.

Question 6 of 20

When emergency-braking a smooth-bore tanker:

Brake hard
Anticipate forward surge that can throw your weight against the wheel and may push the rig past your intended stopping distance
Use only trailer brake
No special concern

Correct. Forward surge can dramatically push a smooth-bore tank rig further than expected. Plan stopping distance with significant additional margin.

Question 7 of 20

Empty tankers handle:

The same as loaded tankers
Differently — lighter axle weight reduces braking traction; tankers are also more affected by crosswinds when empty
Always better
Always worse

Correct. Empty tankers have less brake traction (less weight on tires) and are more affected by crosswinds. Never assume empty equals safer.

Question 8 of 20

Liquid in a partially filled tank causes:

No special concern
Surge — the load slosh that affects vehicle handling
Better fuel economy
Improved braking

Correct. Surge is the side-to-side or front-to-back movement of liquid in a partially filled tank — it can throw the rig forward, pull it sideways, and significantly affect handling.

Question 9 of 20

When driving a tanker through a sharp bend at the recommended speed for cars:

You are likely to roll over
You are safe
You will accelerate
Brakes engage automatically

Correct. Tanker rollovers regularly happen at posted "car" curve speeds. Slow well below posted speeds in a loaded tanker.

Question 10 of 20

On a wet road, a tanker should:

Maintain normal speed
Reduce speed by about one-third
Drive faster
Use only the trailer brake

Correct. On wet pavement, reduce speed by about one-third. On snow, by about one-half. Tankers are less forgiving than dry vans on slippery roads.

Question 11 of 20

A tanker with an empty compartment between two full compartments may:

Slosh forward and backward, hard to predict
Be smoother
Drive itself
Have no surge

Correct. Mixed full and empty compartments produce complex surge patterns. Plan acceleration and braking conservatively.

Question 12 of 20

A tanker with a high center of gravity is most prone to rollover during:

Straight-line driving
Tight curves, evasive maneuvers, and exit ramps
Backing
Stopping

Correct. High center of gravity makes tankers roll on tight curves, sudden lane changes, and exit ramps. Slow well in advance.

Question 13 of 20

When you stop a placarded tanker carrying flammable liquid at a railroad crossing, you must stop:

On the rails
Between 15 and 50 feet from the nearest rail, then proceed only when safe
Anywhere
Only if a train is in sight

Correct. Placarded hazmat (which most fuel tankers are) must stop 15 to 50 feet from the nearest rail. Look, listen, and cross only when clear.

Question 14 of 20

Loading dock procedure for cargo tanks of flammable liquid:

Set parking brake, chock wheels, shut off engine, ground and bond, monitor loading, follow loading-rack procedures
Leave the engine running
Skip the chocks
Smoke nearby

Correct. Standard loading-rack procedure: brake set, chocks in, engine off, bond and ground, monitor loading, follow rack-specific procedures (vapor recovery, load arms, etc.).

Question 15 of 20

Tank vehicles should not be driven:

On long downgrades without a lower gear and intermittent firm braking
On any highway
Anywhere
At night

Correct. On long downgrades, select a low gear before starting down and use firm intermittent brake applications to prevent fade.

Question 16 of 20

When loading a cargo tank with flammable liquid, the driver must:

Stay alert, within 25 feet, with a clear view of the tank, and ready to handle emergencies
Leave for lunch
Smoke
Run the engine at high RPM

Correct. Federal rule: driver remains within 25 feet, alert, with a clear view, ready to act in case of overflow or emergency.

Question 17 of 20

Outage requirements:

Vary by liquid because of differing thermal expansion rates
Are always 1 percent
Do not exist
Are only for water

Correct. Outage requirements differ by product. Gasoline expands more than diesel, ethanol expands differently, etc. Check the shipping paper or product specifications.

Question 18 of 20

When you discover a leak in a cargo tank carrying flammable liquid:

Continue to the destination
Stop in a safe location, secure the area, contact emergency response and the carrier — never transfer cargo on the road
Try to drive around the leak
Pour water on it

Correct. A leaking flammable cargo tank is a major incident — secure the area, evacuate per the ERG, contact emergency services. Never attempt roadside cargo transfer.

Question 19 of 20

A double trailer tanker requires:

Both N (Tanker) and T (Doubles/Triples) endorsements, plus possibly H (Hazmat)
Only the N endorsement
No endorsements
Only the H endorsement

Correct. Pulling more than one tank requires Doubles/Triples (T) plus Tanker (N) endorsements. Add Hazmat (H) — together written X — for hazardous liquid loads.

Question 20 of 20

A pressure-relief device that vents during transit:

Is a normal occurrence
Is a serious malfunction or over-fill — stop and investigate
Means the tank is empty
Means the load is cold

Correct. Continuous venting indicates over-pressure (often from over-fill or sun heating an over-filled tank). Stop and investigate; do not continue with a venting tank.

About the Vermont Tanker exam

Most states administer 20 Tanker questions and require 80% to pass. Topics include the unique handling of liquid loads, surge effects, baffles vs. smooth-bore, outage and expansion, inspection of the cargo tank, and emergency procedures.

The Vermont Department of Motor Vehicles follows the federal CDL standards established by FMCSA. To earn the Tanker 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 Tanker question bank or browse all Vermont CDL practice tests.