Maryland Tanker CDL Practice Test

This is a free 20-question practice test for the Tanker portion of the Maryland 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 Maryland Motor Vehicle Administration 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 Maryland.

Question 1 of 20

A "smooth bore" tank has:

No internal divisions
Internal baffles
Compartments
Reinforcement rings

Correct. A smooth-bore tank has no internal divisions or baffles. Surge is dramatic; brake gently to avoid being pushed forward by the load.

Question 2 of 20

A "tank vehicle" requiring an N endorsement is generally defined as:

Any commercial vehicle
A vehicle used to transport liquid or gaseous materials in a tank with rated capacity of 1,000 gallons or more, individual tanks of 119+ gallons
Only fuel trucks
Only vehicles over 80,000 lbs

Correct. The N endorsement is required for any commercial vehicle hauling liquid or gas in a permanently mounted tank or portable tank with rated capacity of 1,000+ gallons (and individual tanks of 119+ gallons).

Question 3 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 4 of 20

Pressure relief devices on cargo tanks are designed to:

Open if pressure inside exceeds safe limits, releasing product or vapor before the tank ruptures
Increase pressure
Be tightened down
Stay closed at all times

Correct. Pressure relief valves open at a set pressure to prevent tank rupture. Tampering with them is illegal and dangerous.

Question 5 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 6 of 20

A heavy liquid load with a baffled tank may still surge:

Front-to-back, despite the baffles
Not at all
Less than smooth-bore but baffles do not stop side-to-side surge
None of the above

Correct. Baffles reduce front-to-back surge but do not affect side-to-side surge — bulkheads are typically transverse, not longitudinal.

Question 7 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 8 of 20

In the event of a fire on a tanker:

Pull off the road, away from buildings, get out, call 911, and use the ERG to identify the response
Continue to deliver
Pour water on a fuel fire
Drive faster to put out the wind

Correct. Pull to a safe area, away from buildings and people. Get out, call 911, and consult the ERG. Some tank fires (e.g., water on flammable liquid) make matters worse.

Question 9 of 20

Outage refers to:

Empty space left at the top of a tank to allow liquid expansion
The brake-out system
A power failure
A driver shortage

Correct. Outage is the empty space left at the top of a tank to allow liquid to expand as it warms. Different liquids require different outage percentages.

Question 10 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 11 of 20

You should never load a tank completely full because:

It is illegal in all states
Liquids expand when warmed and need outage; over-filling can rupture the tank
Trucks won't move
It saves no time

Correct. Liquids expand with temperature. Without outage, a warming load can over-pressurize and rupture the tank.

Question 12 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 13 of 20

The driver should plan extra time for:

Acceleration, braking, and turning a fully loaded tanker
Lunch
Sleep only
Refueling only

Correct. A loaded tanker accelerates slower, brakes longer, and turns wider. Plan your trip and reactions accordingly.

Question 14 of 20

Tank specification "MC-307" or "DOT-407" generally refers to:

Cargo tanks for low-pressure liquids and certain hazardous chemicals
Explosives
Bulk solids
Refrigerated gases

Correct. MC-307/DOT-407 are insulated low-pressure tanks for chemicals — common for many industrial liquids.

Question 15 of 20

Tankers should be driven with:

Less following distance
More following distance and gentler control inputs than a dry van
The same as a car
Higher speeds

Correct. Tankers stop slower and roll easier. Increase following distance and use gentler steering and braking inputs.

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

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 18 of 20

Bonding and grounding during product transfer:

Equalizes electrical potential between the tank and receiving container, preventing static-spark ignition
Charges the battery
Cools the load
Speeds delivery

Correct. Static electricity builds up during liquid transfer. Bonding (cable between tank and receiving container) plus grounding equalizes potential to prevent ignition.

Question 19 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 20 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.).

About the Maryland 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 Maryland Motor Vehicle Administration 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 Maryland CDL practice tests.