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

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

The date of manufacture.

The un or na id number of the product.

The owner's puco or icc number.

The chemtrec phone number.

2 / 40

You do not have to stop at railroad crossings, but must slow down and carefully check for other vehicles:

All of these answers are correct.

If a traffic signal is green.

Where a policeman or flagman is directing traffic.

At crossings marked as "exempt" or "abandoned".

3 / 40

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

All hazard classes.

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

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

It is ok to smoke anywhere.

4 / 40

You should_____to make an emergency stop with air brakes when using the stab braking method.

apply a full hand valve until you stop and press firmly on the brake pedal

apply a firm pressure to the brakes, release the brake pedal once the wheels lock and then apply pressure to the brakes onces the wheels start rolling again

rapidly and lightly pump the brake pedal

apply pressure to the brake pedal until the wheels lock and then stay off of the pedal for as long as the wheels are locked

5 / 40

Select the true statement in regards to the center of gravity for tanks:

None of the answers listed.

The vehicle can handle higher speeds around curves than other large trucks.

The vehicle can turn over even when driving at the posted speed limit for curves.

The center of gravity is generally lower than with other large trucks.

6 / 40

Select what you should do before leaving the vehicle unattended:

apply the parking brakes

remove the keys from the ignition

all of these answers are correct

chock the wheels

7 / 40

You should check____when loading the small tanks of a cargo tank with bulkheads.

none of the answers listed

the weight distribution

the fuel to air ratio

the expansion rate

8 / 40

Which of the following statements about overhead space is true?

an empty van is lower than a loaded one

the heights posted at bridges are usually accurate

the weight of the cargo changes a truck's height

warning lights are always installed on low bridges and overpasses

9 / 40

The driver's manual advises you to disconnect the steering axle brake to keep the rig straight:

never

in ideal conditions

when it is raining

whever you feel like it

10 / 40

Select the true statement about empty trucks:

They have better traction on wet roads than full tanks.

They come to a stop faster when you use only the emergency brake.

They can take longer to stop than a truck with a full tank.

All answers listed.

11 / 40

How do you check the air compressor governor "cut in" and "cut out" pressures?

decrease the tank pressure by stepping on and off the brake

monitor the air pressure gauge

run the engine at a fast idle

all of these answers are correct

12 / 40

What is the best way to stop all skids?

use controlled or stab braking

quickly turn the steering wheel side to side

accelerate and countersteer

restore traction back to the tires

13 / 40

What is the most important reason for doing a vehicle inspection?

to save you money by preventing costly repairs

federal and state laws require you to inspect your vehicle

to insure that you will achieve the best gas mileage

safety for yourself and other road users

14 / 40

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

none of the answers listed

1/8 inch

1/30 inch

1/12 inch

15 / 40

It has just reached freezing. Which of the following areas is slippery?

all of these answers are correct

wet-looking road

a bridge

a shaded area

16 / 40

If you do become sleepy while driving, you should _____.

turn up the radio

roll down the windows

stop to sleep

drink caffeinated beverages

17 / 40

Take extra caution when driving smooth bore tanks during:

Drive down or up an incline.

All answers listed.

Stops and starts.

Driving into the wind.

18 / 40

What keeps air in the tanks should the air compressor develop a leak?

the tractor relay valve

the engine protection valve

the air compressor

the one-way check vavle

19 / 40

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

Every 200 miles.

Twice every day.

Every two hours or 100 miles.

Every six hours.

20 / 40

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

you should use a high gear to make the process faster

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

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

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

21 / 40

The trailer height is correct for connecting a converter dolly to a second trailer when:

the trailer will slightly lower when the converter dolly backed under it

the top of the kingpin lines up with the locking jaws

the trailer will slightly rise when the converter dolly is backed under it

the kingpin is resting behind the fifth wheel

22 / 40

Which contains more alcohol: a 12-ounce glass of 5% beer, a 5-ounce glass of 12% wine or a 1 1/2-ounce shot of 80 proof liquor?

1 1/2-ounce shot of 80 proof liquor

12-ounce glass of 5% beer

5-ounce glass of 12% wine

they all contain the same amount of alcohol

23 / 40

For emergency braking when driving a double trailer and having to use your brakes to avoid a collision is to:

apply a firm pressure to the brake pedal and don’t let off

use just the trailer brakes

use stab or controlled braking

use the engine brake

24 / 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

25 / 40

How should you know when to shift?

engine speed and the shift indicator light

engine speed and road speed

road speed and wind speed

every 3 to 5 seconds or engine speed

26 / 40

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

Spring pressure

Brake pressure

All of these answers are correct

Air pressure

27 / 40

While driving on a clear night with low beam headlights, you should be able to stop within:

Half of a football field.

2 lengths of your vehicle.

The distance you can see ahead of you.

The distance you will travel in the next 20 seconds.

28 / 40

The 3 parts of the air brake system are: service brakes, parking brakes, and ____.

foot brakes

disc brakes

bolt brakes

v-cam brakes

29 / 40

Liquid surge affects the handling of a tanker by:

Moving the truck in the direction of liquid flow.

Decreasing the wind drag.

Allowing you to stop faster.

Allowing you to take tighter turns.

30 / 40

Which of the following statements is FALSE?

if a tire blows, you should put the brakes on hard to stop quickly

stopping is not always the safest thing to do in an emergency

you can almost always turn to miss an obstacle more quickly than you can stop

anti-lock braking systems (ABS) only activate when wheels are about to lock

31 / 40

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

5 hours, 250 miles

3 hours, 200 miles

1 hour, 50 miles

2 hours, 100 miles

32 / 40

This component should be checked that it is solid, securely bolted to the tracture frame, and clear of objects.

The fifth wheel

The platform

The locking kingpin

The catwalk

33 / 40

The parking brakes should be used____in air brake vehicles.

as rarely as possible

only during post trip inspection

only when parked on an incline

every time the vehicle is parked

34 / 40

This item should not be rusted, bent, or damaged and centered over evenly spaced tires and dual wheels.

Spacers

Fifth wheel

Lug bolts

Frame

35 / 40

Select the true statement about seeing ahead.

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

all answers listed

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

many individuals do not look far enough ahead while driving

36 / 40

What is the main difference between a portable tank and a cargo tank?

Cargo tanks are filled while on the vehicle, portable tanks are filled while off the vehicle.

Portable tanks must additionally show the owner or lessee's name on them.

All of these answers are correct.

Cargo tanks are permanently attached, portable tanks are temporarily attached.

37 / 40

If you are hauling hazardous materials and have ___ tires on your vehicle, you must stop and check them every time you park.

treaded

dual

radial

bias

38 / 40

What is the purpose of cladding in a tanker?

It eliminates liquid surge.

It protects the tanker form any corrosive cargo.

It controls the temperature of the cargo.

It protects the cargo from changes in temperature.

39 / 40

Drivers placard their vehicle to _____ the risk.

take away

elevate

communicate

minimize

40 / 40

Which of the following statements is true about speed management?

All of these answers are correct.

Speed limits for buses are the same as cars.

You should be able to stop within the distance that you can see ahead.

The posted speed limit is safe for all conditions.

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