iowa
CDL Practice Test

Below are practice questions for the Iowa CDL test. The site is free and you are able to take the practice test as many times as you need to as you prepare to obtain your Iowa CDL. The questions and answers covered in these Iowa practice CDL tests are taken from the Iowa DOT CDL manual. You will be presented with 40 questions and you must answer 34 questions correctly to pass. There is a 50-minute time limit. You may not go back once you answer a question. Click the "Start Test
" button below to begin.

1 / 40

What can side to side surge cause?

A roll over.

An engine system failure.

An increase in speed.

A spontaneous combustion.

2 / 40

What is the safest way to stop unruly behavior on the bus?

have the unruly students move to the front of the bus

keep checking the rear view mirror so you can see what happened and report to the principal

pull off the road in a safe location, secure the bus, stand up, and tell the students what behavior you expect of them

yell loudly for the students to sit down and behave themselves

3 / 40

This object should not be worn dangerously thin where visible.

The air system lines

All answers listed

The brake linings

The brake chambers

4 / 40

What does the air compressor governor control?

when air is pumped into the air tanks

when the valve system releases pressure

when the air is taken out of the hoses

when air pressure is applied to the brakes

5 / 40

Unless you_____you will feel the effects of a liquid surge.

make turns carefully and slowly

haul thick liquids

all answers listed

gradually come to a stop

6 / 40

Under which two special conditions should you downshift?

if there is an accident and in sudden heavy rain

before starting down a hill and before entering a curve

before starting down a hill and before going up a hill

before entering a curve and before going up a hill

7 / 40

When driving normally, some drivers use the hand valve before applying the brake pedal to prevent jack knifing. Select the most appropriate response to this statement.

it will result in less skidding than when just using the brake pedal alone

it is the best possible way to brake and maintain the truck in a straight path

should be used with caution and only if you are aware of the dangers

it should not be done

8 / 40

Select whether the following statement is true or false: Front wheel brakes are good to use in all conditions.

only in ideal conditions

only in bad weather

false

true

9 / 40

Select which is not an engine compartement belt:

An air compressor belt

A power steering belt

A water pump belt

A safety belt

10 / 40

How do you know when your brakes are fading?

the brake pedal flops to the cabin floor

to control your speed on a downgrade you have to push harder on the brake pedal

to control your speed on a downgrade you have to apply less pressure to the break pedal

your speed increases when pressure is removed from the brake pedal

11 / 40

Why is understanding the loading and unloading procedures so critical?

Because only high school students understand how to cross the road.

Because many students are killed while getting on and off a school bus each year.

Because motorists ignore students walking to school.

Because school district officials have the authority to conduct surprise quizzes and you must know the correct answers to keep your job.

12 / 40

By law, the warning lights must only be used when approaching a:

Stop to load or unload students.

Sharp turns.

Any stop the bus makes.

Busy intersection.

13 / 40

The best way to test if the spring brakes come on automatically is to:

apply pressure on and off the brake pedal until the parkng brake valve pops out on tractor-trailer vehicles

all of these answers are correct

apply pressure on and off the brake pedal until the manufacturer's low psi specification has been met for the spring brakes to deploy

apply pressure on and off the brake pedal until the parking valve pops out on single vehicles

14 / 40

Tires should should be replaced:

all of these answers are correct

when there are broken valve stems

when the tread separates

if the tread depth on your front tires is less than 4/32 deep

15 / 40

Select the true statement in regards to an application pressure gauge:

when accelerating it releases air

it shows how much air pressure you are applying to the brakes

it is connected to the generator

it prevents the brakes from failing

16 / 40

If you are driving a 100-foot truck with double trailers at 30 mph in dry conditions, how many seconds of space should there be between your truck and other vehicles?

17 / 40

This object should be free of shiny treads, rust, free of cracks and distortions.

Rims

Lug nuts

Bolt spacers

None of the answers listed

18 / 40

A baffled tanker has:

No side to side surge.

Balls floating in it to increase the speed of the liquid movement.

Bulkheads with holes that allow liquid to flow through it.

Separate compartments inside the trailer.

19 / 40

Your vehicle is going down a long hill and your brakes begin to fail. What should you do?

put the gears in neutral

look for an escape ramp or an escape route

pump the brake pedal

downshift

20 / 40

Check that the parking brake will hold by____when the parking brake is engaged and the trailer brakes released if not a combination vehicle.

shift up into a high gear and let off the clutch quickly

while in neutral increase the rpm to 1500

shifting down to a low gear and trying to pull forward gently

all answers listed

21 / 40

The two main things to look ahead for while driving are _____.

fire and flooding

truck stops and police

traffic and road conditions

bridges and tunnels

22 / 40

Is it mandatory that all vehicles with air brakes have low air pressure warning signals?

for large vehicles only

yes

for small vehicles only

23 / 40

If you are required to stop at railroad crossings, you must:

Remember to never shift gears while crossing tracks.

All of these answers are correct.

Proceed only when you are sure no train is coming.

Stop 15 to 50 feet before the nearest rail.

24 / 40

Which of the following is the most important reason for doing a pre-trip inspection?

because other drivers do it

to make sure nothing has been stolen from the vehicle

safety for yourself and other road users

to make sure the vehicle will make your destination

25 / 40

Select the answer that is controlled by the foot brake.

the service air line

the engine brake

the emergency brake

the shut off valves

26 / 40

Select the vehicle that off-tracks the most.

a 5-axle tractor that is towing a 45-foot long trailer

a 5-axle tractor that is towing a 32-foot long trailer

a 5-axle tractor that is towing a 40-foot long trailer

a 5-axle tractor that is towing a 52-foot long trailer

27 / 40

The best way to test the low air pressure warning signal is to:

manually release the air out of your brakes to see if the signal activates

apply pressure on and off the brakes while the engine is running

apply pressure on and off the brake pedal until the air pressure drops below 20 psi

apply pressure on and off the brake pedal with the engine off to drop the air pressure to below 60 psi

28 / 40

The air leakage rate for combination vehicles should not be more than _ psi a minute.

29 / 40

What will occur as a result of failing to perform all 3 components of the air brake check?

An automatic failure of the vehicle inspection test.

The driver must restart the pre-trip from the beginning.

A deduction of 15 points.

None of the answers listed.

30 / 40

A commercial motor vehicle (CMV) is defined as:

a vehicle transporting hazardous materials

a vehicle with a gross weight over 26,001 lbs

all of these answers are correct

a vehicle transporting 16 or more passengers

31 / 40

You must keep shipping papers describing hazardous materials ______.

within 100 feet of the hazardous materials at all times

with the bills of lading

in a pouch on the drivers door or in the overhead compartment above the driver’s seat only

in a pouch on the driver’s door or in clear view within immediate reach while the seat belt is fastened while driving on the driver’s seat when out of the vehicle

32 / 40

Which of the following are some suspension system defects?

cracked or broken spring hangers

leaking shock absorbers

all of these answers are correct

broken leaves in leaf spring

33 / 40

You may use DANGEROUS placards instead of separate placards for each Table 2 hazard class when:

Both of these conditions must be met.

You have 1,001 pounds or more of two or more table 2 hazard classes, requiring different placards.

You have not loaded 2,205 pounds or more of any table 2 hazard class material at any one place (you must use the specific placard for this material).

The correct answer is not listed.

34 / 40

What action should you take if there is no phone available and you discover your hazardous materials shipment leaking at a rest stop?

Keep driving, slowly and cautiously, until you reach a phone.

Leave your truck parked with emergency lights on and walk for help.

Send someone for help with all the necessary information.

Keep driving for help as quickly as possible.

35 / 40

You should check that the _____are secure, caps are on tight, and is not leaking.

cb radio

fuel tanks

coolant system

none of the answers listed

36 / 40

Never refuel your bus:

Without a static chain.

With any of the windows open.

In a closed building with passengers on board.

With a higher grade of fuel.

37 / 40

Select the true statement about seeing ahead.

many individuals do not look far enough ahead while driving

all answers listed

good drivers will shift their attention from far and near and back and forth

you should look up to 1/4 mile ahead when driving at highway speeds

38 / 40

A shipper’s certification is best described as _____.

a test for shippers that certifies that they are qualified to package hazardous materials

a certification that the package has been prepared according to the rules when the shipper packages hazardous materials

a paper certification given to the manufacturer from the shipper

a paper certification from the manufacturer given to the shipper

39 / 40

If you are carrying Division 1.2 or 1.3 materials, how far away must you park from the traveled portion of the roadway?

At least half a mile

At least five feet

At least twenty feet

At least ten feet

40 / 40

Why should you cover cargo?

all of these answers are correct

because many states require it

to protect individuals from any spilled cargo

to protect your cargo from bad weather

Your score is

The average score is 0%

5/5 - (1 vote)

CDL Category Practice Tests

CDL Practice Test

How To Get An iowa Commercial Drivers License

Individuals may apply for their CDL starting at age 18. To be eligible for interstate driving as well as HazMat and Doubles/Triples applicants must be 21 years of age or older. All individuals applying for an Iown CDL must present a Medical Examiner’s Certificate according to the United States Federal Regulations.

If any one of the descriptions below is true about an applicant, they will be disqualified from receiving their CDL.

Driver posses more than one driver’s license.
Driver was convicted of driving under the influence in the past 24 months.
Driver has a suspended, denied, canceled, or revoked driver’s license.

Endorsements
H – Hazardous Materials
N – Tank Vehicle
T – Doubles/Triples
X – Hazmat and Tank Comb
P – Passenger Vehicle
S – School Bus

Drivers must take a knowledge test as well as a practical skills test to showcase their knowledge of commercial driving laws and their ability to operate a commercial vehicle.

Hit the Open Road

iowa CDL License Test Tips

Applicants must complete a general knowledge test to display their understanding of commercial driving laws. The general knowledge exam is comprised of 50 questions. Those seeking a Class A CDL will need to complete an additional 20 question test on combination vehicles. Applicants seeking additional endorsements will need to take an additional test on the endorsement topic. The Passenger, Tank, and Doubles/Triples Endorsements are 20 question tests. Removing the Air Brake Restriction, the Iowa Operator and School Bus Endorsements are 25 questions. The Hazmat Endorsement is a 30 question test. All applicants must pass the respective assessments with a score of 80 percent or better to receive their Iowa CDL permit.

A skills assessment is required of all applicants. This assessment is comprised of three parts, which are the pre-trip inspection, basic controls skills, and on-road driving. Individuals applying for their P and S endorsements will be required to take the skills test in the respective vehicle for their endorsement.

Additional Information

Information on the Iowa Department of Transportation

The Iowa Department of Transportation administers CDL requirements and testing in Iowa. To get more information contact them via:

Website: https://iowadot.gov/DriversVehicles#CommercialDrivers

Phone: 515.239.1101

Additional Iowa CDL Helpful Links

Please use the links below to access more valuable Iowa CDL testing resources and to learn more about practice driving tests for the state of Iowa.

iowa CDL Practice Test

CDL Category Practice Tests

CDL Practice Test

How To Get An iowa Commercial Drivers License

Hit the Open Road

iowa CDL License Test Tips

Additional Information

Information on the Iowa Department of Transportation

Additional Iowa CDL Helpful Links

iowa
CDL Practice Test