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

To prevent a roll over a driver can 1) keep the cargo as low to the ground as possible and 2) _____.

take turns slowly

drive while intoxicated

have the fifth wheel's free play as tight as possible

have the brakes properly adjusted

2 / 40

Select which is not an engine compartement belt:

A power steering belt

A water pump belt

A safety belt

An air compressor belt

3 / 40

An example of a low pressure warning signal for air brakes is:

red light

all of these answers are correct

a wig wag mechanical arm

a buzzer

4 / 40

When transporting hazardous loads, you must check the tires at least:

Every 200 miles.

Every two hours or 100 miles.

Twice every day.

Every six hours.

5 / 40

What will happen should a driver cross the air lines when hooking up the an older trailer?

none of the answers listed

the brake pedal will activate the trailer spring brakes instead of the air brakes

the hand valve will activate the tractor brakes instead of the trailer brakes

if there are no spring brakes, you can drive on but there will be no trailer brakes

6 / 40

Your rig should be parked on__to uncouple double trailers.

the company's lot

level ground

a downgrade

grass

7 / 40

Select the true statement about dual air brake systems.

one system controls the front axle and the other controls the rear axle

there is a primary system and a secondary system

there is a single set of brake controls

all of these answers are correct

8 / 40

Which of the following is something the driver must watch for:

Poles and tree limbs at stops.

Gaps your bus needs to accelerate and merge with traffic.

Appropriate clearance around and over the bus.

All of these answers are correct.

9 / 40

Which of the following is a key steering component?

torque rod

leaf spring

gear box

bearing plate

10 / 40

If you have to swerve to avoid a hazard, it's important to:

Warn passengers with a loud and clear voice.

Make sure your passengers are wearing seat belts.

Know where other vehicles are around your bus by checking your mirrors.

None of these answers are correct.

11 / 40

____is what can legally hold the parking brake or emergency brake in position for a bus, truck, or truck tractor.

All of these answers are correct

Spring pressure

Air pressure

Brake pressure

12 / 40

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

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

all of these answers are correct

brake hard after accelerating

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

13 / 40

If hazardous material is spilling from your vehicle, do not move your vehicle:

Any more than safety required.

In an upwind direction.

Any more than 500 feet.

Any more that 450 feet.

14 / 40

You should look into the back of the fifth wheel on a dolly to see if it is locked onto the kingpin.

true

only at the end of a shift

only in a level loading dock

false

15 / 40

The two other places where the hazardous identification number must appear are:

On the back of the truck and inside the glove compartment.

Any bulk packaging and the cargo tanks.

On the gas tank and a sticker in the glove compartment.

On a temporary license plate holder and the steering wheel.

16 / 40

If you are already carrying 100 pounds of silver cyanide, what precautions must you take if you are given papers at a dock to carry 100 cartons of battery acid?

Inform someone and not load the battery acid.

Make sure there is plenty of space between the two.

Make sure the silver cyanide is loaded on top of the battery acid.

Make sure the battery acid is loaded on top of the silver cyanide.

17 / 40

What is the best way to see the sides and rear of your vehicle?

your mirrors

all of these answers are correct

rear view cameras

a helper

18 / 40

Tankers used to transport hazardous materials on vehicles must be marked with:

The date of manufacture.

The chemtrec phone number.

The un or na id number of the product.

The owner's puco or icc number.

19 / 40

Should your air compressor stop working:

there will be no affect to your brakes

the brakes will lock up on you immediately

you will lose your ability to brake immediately

there will still be air pressure left in the air tanks

20 / 40

A baffled tanker has:

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

No side to side surge.

Separate compartments inside the trailer.

Bulkheads with holes that allow liquid to flow through it.

21 / 40

The minimum tread depth for steering axle tires is:

4/32 inch

14 mm

2/23 inch

None of the answers listed

22 / 40

Your bus is disabled. With riders aboard, the bus may be towed or pushed to a safe place only:

By another bus with its four-way flashers on.

If the distance is less than 500 yards.

By a 27,000 lbs gvwr or larger tow truck.

If getting off the bus would be more risky for the riders.

23 / 40

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

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

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

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

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

24 / 40

Why should you use chocks when parking a trailer without spring brakes?

to prevent someone from stealing the vehicle

to prevent a runaway trailer

the trailer wheels are free to turn as there will be no emergency brakes should the air supply in the trailer air tank leak

the trailer wheels are free to turn as there will be no service brakes should the air supply in the trailer air tank leak

25 / 40

An "A/W" the first column of the hazardous materials table means:

This material has no restrictions when shipped by air and/or water.

This material is only restricted when shipped by air and/or water.

There is no restrictions with this material if shipped by water only.

It is ok to ship this material by air only.

26 / 40

How should the hand valve be used?

only in emergency situations

when the trailer is fully loaded down

to test the trailer brakes

only in conjuction with the foot brake

27 / 40

Which of the following statements about stopping distances is NOT true?

trucks traveling on ice or snow require greater stopping distances

brakes, tires, springs and shocks are designed to work best when the truck is empty

empty trucks require greater stopping distances because they have less traction

trucks traveling at higher speeds require greater stopping distances

28 / 40

Is this statement true or false: You do not need to use the parking brake if are leaving your vehicle for a short amount of time.

only when the vehicle has over 60,000 miles on it

true

false

only when the vehicle has over 25,000 miles on it

29 / 40

When driving in very hot temperatures, you should:

let your tires cool down (remain stopped) if they are too hot to touch

all of these answers are correct

insure that you have enough antifreeze in the system

check your tires every 2 hours or every 100 miles

30 / 40

Make sure that_____before you back under a trailer.

the trailer brakes have been locked

the air supply knob has been pushed it

the air supply knob has been pulled out

the air brakes are in an off position

31 / 40

There should be ___space between the upper and lower fifth wheel after coupling.

none of the answers listed

1/30 inch

1/12 inch

1/8 inch

32 / 40

What should the driver pay special attention to when driving smaller tanks?

The level of the fluid.

All answers listed.

The distrubition of weight.

The high center of gravity.

33 / 40

In the event of a tire failure you should...

pump the brakes until you come to a stop

stay off the brake and hold the steering wheel firmly

accelerate quickly until you find a place to pull over

disengage the clutch so you are in neutral gear

34 / 40

Which two special conditions indicate that you should downshift?

starting up a hill and finishing a curve

starting down a hill and finishing a curve

starting down a hill and entering a curve

starting up a hill and entering a curve

35 / 40

Before pulling away, make sure the landing gear of the trailer is:

Raised and that the handle is secured.

Down and that the handle is secured.

Raised and that the handle is hanging free.

Down and that the handle is hanging free.

36 / 40

_____ create a little above 90 degree angle between the adjuster arm and push rod when the brakes are released and no less than 90 degrees when the brakes are applied.

slack adjusters

air lines

brake disc

brake drums

37 / 40

There are 2 reasons as to why hauling liquids take special care. One reason is the ___center of gravity.

low

long

narrow

high

38 / 40

What can you do at an accident site to help avoid another accident?

stay in your vehicle and do nothing until help arrives

leave your vehicle, do nothing, and get to higher ground

put out warning devices so people don't run into the accident site

have a drink to calm your nerves

39 / 40

Select the true statement in regards to your brake function when your ABS fails

you will have no control over your truck as the brakes will not be functioning

the abs will need to be repaired but the brakes will function normally

there is a huge fire risk

you will need to pull over immediately

40 / 40

When should air tanks be drained?

at every restroom break stop

at the end of each working day

every 7 days

they don't need to be drained

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