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

Which of the following is NOT a basic step to be taken at a crash scene?

gather the contact information of all the drivers involved

care for the injured

notify authorities

protect the area

2 / 40

Select the statement that describes smooth bore tanks:

They are 1 large tank.

They are divided down into smaller tanks.

None of the answers listed.

They are divided with holes from liquid to flow through controlling surge.

3 / 40

To avoid rollover when going through a curve, the best thing to do is:

Ride the brakes through the curve.

Pump the brakes through the curve.

Drive at a speed higher than the posted speed limit.

Drive at a speed below the posted speed limit.

4 / 40

Never refuel your bus:

Without a static chain.

In a closed building with passengers on board.

With a higher grade of fuel.

With any of the windows open.

5 / 40

Select the accurate statement in regards to rolling up the landing gear to complete the coupling process.

you should use a low gear until the tractor is supporting the trailer

you should leave the landing gear at the half way mark to make the uncoupling process easier later

you should grease the landing gear the increase the speed of the process

you should use a high gear to make the process faster

6 / 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?

7 / 40

What will happen right away should the service air line come apart but the emergency line is intact while driving a combination vehicle?

nothing will occur until you try to use the brakes

you will come to a complete stop

the emergency tractor brakes will activate

the trailer's air tank will leak through the one line

8 / 40

Before backing under the trailer you should______when coupling a tractor and trailer with air lines already connected.

all answers listed

press down on the brake pedal twice

have the trailer brakes off

supply air to the trailer system and then pull the air supply knob out

9 / 40

Who is responsible for certifying on the bills of lading that the hazardous materials are prepared properly?

The driver

The carrier

The shipper

The dock workers

10 / 40

What is the benefit of ABS?

it prevents the wheels from locking up during heavy braking or slippery conditions

it decreases your stopping distance

all of these answers are correct

it provides an added layer of safety for truck drivers

11 / 40

It is very important that you never smoke around which hazard classes?

All hazard classes.

It is ok to smoke anywhere.

Explosives, flammable gas, oxidizers, flammable solids, flammable liquids.

Corrosive, radioactive, dangerous, slippery when wet, inhalation.

12 / 40

Five hazard classes that require placarding in any amount are ______.

explosives 11, corrosive 8, flammable 3, explosives 14, and poison 61

poison gas 23, dangerous when wet 43, explosives 13, explosives 12, and explosives 11

none of these answers are correct

corrosive 4, hazardous 14, flammable 2, explosives 7, and radioactive 12

13 / 40

This object is not checked at the rear of the trailer.

The back doors

The mud flaps

The header board

The bumper

14 / 40

On a bus, you may sometimes haul small-arms ammunition, emergency shipments of drugs, or hospital supplies. The total weight of all such hazardous materials must not be greater than:

500 pounds

100 pounds

300 pounds

250 pounds

15 / 40

At what "cut out" level does the governor stop pumping air?

150 psi

125 psi

75 psi

100 psi

16 / 40

Select the statement of what you should not do if you are required to drive through flowing water or deep puddles.

shift into a lower gear

quickly turn the steering wheel side to side

increase engine rpm

drive at a high speed

17 / 40

The longest crack that brake or disc drums can have is:

None of the answers listed.

1/2 the width of the friction area.

Cracks are not permitted.

1/2 inch across in a straight line.

18 / 40

Remember to_____to prevent rollovers.

all answers listed

drive slowly around turns

have the load as low to the ground as possible

have the load centered

19 / 40

It is good practice to_____when uncoupling.

have the glad hands coupled to the dummy couplers

all answers are appropriate

have the glad hands coupled together

make sure the electrical cable is hanging with the plug end down

20 / 40

What type fire extinguisher is required in the power unit of a placarded vehicle?

Any of these are acceptable.

A ul rating of 15 abc.

A ul rating of 5 b/c or above.

A ul rating of 10 b/c or above.

21 / 40

Which of the following statements about overhead space is true?

warning lights are always installed on low bridges and overpasses

an empty van is lower than a loaded one

the weight of the cargo changes a truck's height

the heights posted at bridges are usually accurate

22 / 40

The floor liner for explosives may not:

Contain any of these materials.

Contain nails or screws.

Contain cracks or holes.

Contain steel or iron.

23 / 40

Your rig should be parked on__to uncouple double trailers.

grass

the company's lot

a downgrade

level ground

24 / 40

How can you determine if your vehicle is equipped with ABS?

check for yellow abs malfunction lamps on the instrument panel

look for wheel speed sensor wires that are coming from the rear of your brakes

all of these answers are correct

check if your vehicle was manufactured after March 1, 1998 (they are required to have the panel light)

25 / 40

Which of the following types of cargo must never be carried on a bus with passengers?

Small arms ammunition (orm-d)

Tear gas

Emergency hospital supplies

Emergency drug shipments

26 / 40

Which of the following about the front tires on a commercial bus is true?

Must not have recapped or regrooved tires.

Can be recapped, but never regrooved.

Must not be recapped, but can be regrooved.

Can be regrooved or recapped as long as they have 4/32 tread depth.

27 / 40

When inspecting the ______you are making sure that the lines and hoses are not chafed, cut, pinched, or dragged against tractor parts.

mud flaps

electric/air lines

air brake lines

lifts/door/ties

28 / 40

Which of the following is a reason that shippers package material?

Because it is the shipper's responsibility to determine whether or not a material is hazardous.

All of these answers are correct.

Because it is the shipper's responsibility to correctly label the transport vehicle with precautionary placards.

Because it is the shipper's responsibilty to choose the correct packaging for a material classified as "hazardous".

29 / 40

What gauge on the dashboard indicates electrical system charging rate?

The power gauge

The coolant pressure gauge

The ammeter/voltmeter

The air gauge

30 / 40

Where are shut off valves located on trailers that are doubles or triples?

on emergency and service air lines

on emergency air lines

on service air lines

on parking brake lines

31 / 40

Do you need to stop before a railroad crossing if you are hauling 100 pounds of Division 4.3 Dangerous When Wet material?

Only in populated areas

Yes

Only if you have more than 1,001 pounds of it

32 / 40

You should check your tires every ____ or every ____ when driving in very hot weather.

1 hour, 50 miles

2 hours, 100 miles

5 hours, 250 miles

3 hours, 200 miles

33 / 40

When driving with multiple trailers, which one should be right behind the tractor?

the trailer with the heaviest load

the trailer longest in length

the trailer with the smallest road

the trailers shortest in length

34 / 40

How often should you check the tires on a placarded trailer that has dual tires?

Start of each day and every time you stop.

Each time you stop.

Once every three hours.

Once every 100 miles.

35 / 40

The school bus driver may be the only contact person from school system some parents meet. The percentage of such parents is as high as:

0.5

0.65

0.72

0.85

36 / 40

Why is the proper adjustment and use of all mirrors so vital to the safe operation of the school bus?

In order to observe the danger zones around the bus and look for the students, traffic, and other objects in this area.

In order to see if small vehicles are driving in the bus blind spots.

In order to observe the danger zones around the bus.

In order to clear up blind spots around the bus.

37 / 40

At around____the governor allows the air compressor to start pumping again:

125 psi

225 psi

100 psi

175 psi

38 / 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 ten feet

At least five feet

At least twenty feet

39 / 40

Select how you would check the truck's slack adjusters.

while wearing gloves, pull hard on each slack adjuster that you can reach

brake hard after accelerating

all of these answers are correct

listen for any strange noises while applying pressure to the brake pedal

40 / 40

The bus driver must accept responsibility for supervising and controlling students while on the bus route. Who is the person in charge?

Bus driver.

Parents of the students on the bus.

Students on the bus.

The school district superintendent.

Your score is

The average score is 55%

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