Nebraska General Knowledge CDL Practice Test

This is a free 20-question practice test for the General Knowledge portion of the Nebraska 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 Nebraska 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 Nebraska.

Question 1 of 20

Which of the following is NOT part of the seven-step pre-trip inspection method?

Approach the vehicle and overview
Check the engine compartment
Test the AM/FM radio
Walk around inspection

Correct. The radio is not part of the safety inspection. The seven-step method covers approach, engine compartment, in-cab checks, lights, walk-around, signal lights, and brake checks.

Question 2 of 20

How many red reflective triangles must you carry in your commercial vehicle for emergency warning?

One
Two
Three
Six

Correct. You must carry three red reflective triangles, six fusees, or three liquid-burning flares for emergency warning use.

Question 3 of 20

What is the only effective way to remove alcohol from the body?

Drinking coffee
Cold showers
Eating a heavy meal
Time

Correct. Only time eliminates alcohol from the body — at roughly one drink per hour. Coffee, food, and showers do not speed up the process.

Question 4 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 5 of 20

To recover from a drive-wheel skid, you should:

Brake harder to slow down
Steer in the opposite direction of the skid
Stop accelerating, push in the clutch, and counter-steer
Apply the parking brake

Correct. Stop applying power, push in the clutch (or shift to neutral) to let the wheels turn freely, and counter-steer in the direction you want the front of the vehicle to go.

Question 6 of 20

When should you place reflective triangles on a divided highway after stopping due to a breakdown?

10, 50, and 100 feet behind the vehicle
10 feet to the rear, 100 feet to the rear, and 200 feet to the rear
10, 100, and 200 feet to the rear, on the traffic side
100, 200, and 500 feet to the rear

Correct. On a divided highway with traffic from one direction, place triangles 10, 100, and 200 feet behind the vehicle, on the shoulder or in the lane you stopped in.

Question 7 of 20

When should you use four-way flashers?

Only when parked
When the vehicle is stopped or moving slowly enough to be a hazard to other traffic
Only at night
Whenever you want

Correct. Four-way emergency flashers warn other drivers when your vehicle is stopped or moving slowly relative to traffic.

Question 8 of 20

A fully loaded tractor-trailer traveling at 55 mph on dry pavement requires roughly what total stopping distance (perception + reaction + braking)?

100 feet
200 feet
300 feet (about the length of a football field)
600 feet

Correct. Total stopping distance for a heavy commercial vehicle at 55 mph on dry pavement is approximately 300 feet, or the length of a football field including end zones.

Question 9 of 20

Which lane is generally the best for a commercial vehicle on a multi-lane highway?

The far left (passing) lane
The middle lane
The right lane (slow lane)
Whichever has the lightest traffic

Correct. The right lane is generally best — it limits lane changes, reduces conflict with merging traffic only on the right, and matches commercial-vehicle speed.

Question 10 of 20

When should you use your high beams?

Whenever it is dark
When other drivers are within 500 feet ahead
When other drivers are not within 500 feet of you and you are not following another vehicle within 500 feet
In fog

Correct. Federal and state law requires you to dim high beams when within 500 feet of an oncoming vehicle, or when following within 500 feet of another vehicle.

Question 11 of 20

A driver who has been disqualified is:

Allowed to drive a commercial vehicle
Not allowed to drive a commercial vehicle
Allowed to drive only with another driver in the cab
Allowed to drive only on private property

Correct. A disqualified driver may not operate a commercial motor vehicle on public roads, regardless of supervision.

Question 12 of 20

Which type of fire extinguisher should you use on an electrical fire?

Class A
Class B
Class C
Class D

Correct. Class B:C dry-chemical extinguishers (often labeled "B:C" or "ABC") are appropriate for electrical fires. Never use water on an electrical fire.

Question 13 of 20

If you are involved in an accident, you should:

Drive away if no one is hurt
Notify authorities, protect the scene with warning devices, and care for the injured
Move all vehicles immediately
Make no statements at all

Correct. Stop, protect the scene, notify authorities, care for injured persons, and exchange the required information. Failing to stop is a serious offense.

Question 14 of 20

When stopping at the scene of an accident, you should:

Move your vehicle into traffic to make room
Park well off the road, set out warning devices, and offer assistance
Leave the scene immediately
Drive around the accident

Correct. Park clear of the road, activate four-way flashers, set out warning triangles, and assist as you can without putting yourself in danger.

Question 15 of 20

When the brake pedal feels spongy on an air-brake vehicle:

It is normal
Stop and have the system checked — there may be air in the system or another issue
Drive faster
Pump the brakes harder

Correct. A spongy or unusual feel in air-brake pedals indicates a system issue. Have it inspected before continuing.

Question 16 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 17 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 18 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 19 of 20

Which of these is NOT a hazard you should look out for ahead?

Pedestrians
A vehicle stopped on the shoulder
Roadway construction
A clear, dry road

Correct. Hazards are conditions that could lead to a crash: pedestrians, stopped vehicles, work zones, debris. A clear, dry road is the absence of a hazard.

Question 20 of 20

On a vehicle equipped with ABS, you should:

Pump the brakes during emergency stops
Apply the brakes the way you always have, with steady pressure
Use the parking brake instead
Never use the service brakes

Correct. With ABS, brake the way you always would. The system prevents wheel lockup automatically; pumping interrupts ABS function.

About the Nebraska 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 Nebraska Department of Motor Vehicles 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 Nebraska CDL practice tests.