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

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

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).

Both of these conditions must be met.

The correct answer is not listed.

2 / 40

Air tanks should be drained:

at the end of each shift or day

all of these answers are correct

to prevent sludge from clogginng up the brake system valves

manually when the automatic devices fail

3 / 40

Take extra caution when driving smooth bore tanks during:

Driving into the wind.

Stops and starts.

All answers listed.

Drive down or up an incline.

4 / 40

Select the true statement in regards to when a bulk tank vehicle stops at an intersection on a slippery surface:

The trailer may slide to the side due to the rocking motion.

The movement of the liquid may push the truck into the intersection.

The liquid may leak out of the tank.

The trailer may slide into the oncoming traffic.

5 / 40

Which trailer is most likely to turn over when you make a sudden turn while pulling doubles?

the rear trailer is twice as likely

there is an even chance for either trailer

trailers will never turn over

the front trailer is twice as likely

6 / 40

When a substance in the materials table is written in italics it means :

It is not the proper shipping name only those in roman type above it are proper shipping names.

The substance is for international transport.

It is the proper shipping name.

It is a foreign substance.

7 / 40

Select the true statement about seeing ahead.

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

all answers listed

many individuals do not look far enough ahead while driving

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

8 / 40

Shifting into a lower gear and removing your foot off of the accelerator to slow your vehicle is known as?

anti-lock braking

engine braking

brake fade

double clutching

9 / 40

Select the true statement in regards to driving a truck with triple or double trailers:

the risk of trailer jackknifes and tipping is increased compared to shorter trucks

extra care should be taken when driving in bad weather and in the mountains

all answers listed

the truck requires increased following distance compared to smaller vehicles

10 / 40

You should____to check the free play of manual slack adjusters on S-Cam brakes.

apply the parking brake after stopping on level ground

after parking on a slight grade, release the parking brake, activate the service brakes and check for vehicle movements

drain off air pressure before adjusting after parking on level ground

chock the wheels and release the parking brakes after parking on a level ground

11 / 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 the silver cyanide is loaded on top of the battery acid.

Make sure there is plenty of space between the two.

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

12 / 40

What should you do if you start a trailer skid?

quickly step on the brakes

use your trailer hand brake

release the brakes to get traction back

slowly apply a firm pressure to the brakes

13 / 40

Select the true statement about double or triple trailers.

they can roll over due to abrupt steering movements

all answers listed

they present a rearward amplification hazard

they can have a dangerous "crack the whip" effect

14 / 40

A commercial motor vehicle (CMV) is defined as:

all of these answers are correct

a vehicle with a gross weight over 26,001 lbs

a vehicle transporting hazardous materials

a vehicle transporting 16 or more passengers

15 / 40

A tractor should not be backed under a trailer until the whole air system is:

at a level of 50 and 70 psi

at a level of 70 and 90 psi

at a normal pressure

at half of its normal pressure

16 / 40

What is a passive railway crossing?

The type of crossing, which does not have any type of traffic control device.

The type of crossing on which the driver does not have to stop.

The type of crossing where you can pass the tracks without stopping.

The type of crossing with no cross buck sign.

17 / 40

If you are drowsy, you should _____ before you drive.

take a cold shower

do a little exercise

drink coffee

get sleep

18 / 40

In what location must you keep your shipping papers which describe any hazardous materials?

In a locked glove compartment anytime you are outside of the vehicle.

In a fire-safe pouch under the driver's seat that you can reach while you are driving.

In a fire-safe pouch under the passenger seat while you are driving.

On the driver's seat anytime you are outside of the vehicle.

19 / 40

Where should the safety catch for the fifth wheel locking lever be located for coupling to be complete?

below the locking lever

through the locking lever

above the locking lever

outside of the locking lever

20 / 40

How should you inspect a converter dolly?

as if it is cargo

as if it is an axle with a fifth wheel

as if it is an engine

as if it is a trailer

21 / 40

How do you test your service brakes?

release the air pressure and activate the parking brake

pull over and activate the parking brake

apply pressure to the brake pedal when moving at highway speeds

after releasing the parking brake, move forward slowly and apply pressure to the brake pedal

22 / 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 entering a curve and before going up a hill

before starting down a hill and before going up a hill

23 / 40

Select the true statement in regards to stopping distance and speed:

You require 4 times as much stopping distance when driving at 40 mph compared to 20 mph.

All answers listed.

Larger / heavier vehicles generally take longer to stop.

A wet road will double the stopping distance at any speed.

24 / 40

Which trailer is most likely to tip over due to the crack the whip effect?

the last trailer of a double

the first trailer of a triples

the heaviest trailer

the last trailer of a triple

25 / 40

A shipment described on the Hazardous Waste Manifest may only be delivered to another _______ carrier or treatment facility, who then signs the ______, giving you a copy which you must keep.

trucking, uniform hazardous waste manifest

responsible, papers

registered, uniform hazardous waste manifest

licensed, manifest

26 / 40

What are spring brakes?

they are big springs with air pressure in them if the air pressure decreases, the brakes are applied

they are powerful springs that are restrained by air pressure when the air pressure is removed, the brakes are applied

none of the answers listed

they are large springs that are held closed by air pressure if the air pressure is increased the brakes are applied

27 / 40

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

The date of manufacture.

The owner's puco or icc number.

The un or na id number of the product.

The chemtrec phone number.

28 / 40

When should the trailer hand valve be used?

all answers listed

when driving at highway speeds

when parked in a service lot

to test the trailer brakes

29 / 40

How often should air tanks be drained?

every 7 days

every 6 hours

once a day

every 4-5 days

30 / 40

When driving on a clear night with the vehicle lights on, your speed should be such that you can stop within _____.

2 times the length of your vehicle

the distance you can see ahead of you

the distance you will travel in 10 seconds time

the length of half a football field

31 / 40

Make sure that_____before you back under a trailer.

the air supply knob has been pushed it

the air brakes are in an off position

the air supply knob has been pulled out

the trailer brakes have been locked

32 / 40

Overhead inside mirror is used to:

see all of the students

see the area where students exit the bus

see the blind spot immediately behind the bus

monitor traffic that approaches and enters the blind spot area

33 / 40

The most important hand signal you should agree on with a helper is:

“turn up the music”

“go”

“stop”

“faster”

34 / 40

In what position should the converter dolly air tank drain valve be in for double trailer combination?

in an open position

in a halfway closed position

in a 1/3 open position

in a closed position

35 / 40

To maintain alertness during the trip, drivers should:

schedule trips during the daytime hours

avoid medications that cause drowsiness

all of these answers are correct

get 8-9 hours of sleep

36 / 40

A disruptive passenger:

Should not be discharged where it would be unsafe for them.

Is not your responsibility.

Should not be allowed on the bus.

May be thrown off the bus.

37 / 40

On tandem axle for trailers, the sliding mechanism and locking device is:

Air brake system

Metal frame

Tandem release (locking pin/arm)

Fifth wheel

38 / 40

You should_____to uncouple the converter dolly.

chock the wheels, disconnect the safety chains, and then lower the landing gear

disconnect the safey chains, lower the landing gear, and chock the wheels

chock the wheels, lower the landing gear, and disconnect the safey chains

lower the landing gear, disconnect the safety chain, and chock the wheels

39 / 40

Select the true statement about baffled tankers:

It has walls with holes inside for liquid to flow through.

It has separate tanks.

None of the answers listed.

It has hollow balls in it to slow the motion of the liquid in the trailer.

40 / 40

Select the false statement about suspension:

Check for distorted or broken coil springs.

Check for broken or cracked spring hangers.

Check to make sure torsion bars and/or arms are lubricated.

Check for shifted, missing, or cracked leaf springs.

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