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 is the normal operating range for a truck's oil pressure?

20-30 psi

40-60 psi

This is engine-specific

30-75 psi

2 / 40

You should be in the proper gear before going down a hill because:

water may build up in the air tanks if you do not rely on the engine brake

it builds up the air pressure in the air tanks

it helps control your speed better

brakes may fail or fade from excessive heat due to relying on them too much and not using the engine brake effect

3 / 40

Operating a motor vehicle with the intent of doing harm to others or physically assaulting a driver or their vehicle is known as?

defensive driving

aggressive driving

tailgating

road rage

4 / 40

When should you not use the parking brakes?

while in hot weather

when air pressure is low

while on a steep hill

when the brakes are hot

5 / 40

Select the true statement about emergency steering and tankers:

It is easier to counter steer than other vehicles.

Have a firm grip on the steering wheel before making quick movements of the steering wheel.

None of the answers listed.

Do not apply the brakes when making quick movements of the steering wheel.

6 / 40

What might happen if a trailer is too high when you try to couple?

the trailer may tip to the side

the queen pin may fall off

it may not correctly couple

all answers listed

7 / 40

How much space should there be between the lower and upper fifth wheel?

1 to 2 inches

1/4 to 1/2 of an inch

it is dependent on the load you are carrying

zero

8 / 40

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

all of these answers are correct

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

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

check for yellow abs malfunction lamps on the instrument panel

9 / 40

To be sure that air is supplied to the second trailer:

keep an eye of the air gauge for a drop of 30 psi

crank the engine brake

open the emergency line shut off at the back of the second trailer

while driving at 10 mph, use the hand valve. The vehicle should stop in the same distance of a single trailer moving at 5 mph

10 / 40

Select the statement that is true in regards to what is required of a driver with a double or triple trailers:

drive with extra care in mountains and in bad weather

none of the answers listed

increase your following distance

all of the answers listed

11 / 40

A driver that hauls hazardous materials must attend training every:

1 year

3 years

None of these answers are correct

2 years

12 / 40

Another term for a smooth bore tank is:

A liquid tank that has baffles.

A tank that is made out of stainless steel.

A tank that is easily portable.

A liquid tank that does not have baffles.

13 / 40

Start by___when coupling.

coupling the converter hook to the pintle tongue of the first trailer

having the second trailer against the dock

backing the converter dolly under the second trailer

coupling the tractor to the second trailer

14 / 40

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

Raised and that the handle is secured.

Raised and that the handle is hanging free.

Down and that the handle is secured.

Down and that the handle is hanging free.

15 / 40

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

never

in ideal conditions

whever you feel like it

when it is raining

16 / 40

What are the 3 methods for securing a second trailer before coupling?

parking against another trailer, locking the trailer door, and chocking the tires

parking on level ground, chocking the tires, and charging the trailer air tank if it doesn't have spring brakes

all answers listed

chocking the tires, parking on level ground, and charging the air tank

17 / 40

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

look for an escape ramp or an escape route

pump the brake pedal

downshift

put the gears in neutral

18 / 40

Select the statement that is true in regards to managing space to the sides.

you should always keep your vehicle to the right side of the lane

all answers listed

high gust winds do not cause any issues for triples and doubles

you should try to avoid driving next to others when possible

19 / 40

You can be sure air is supplied to the second trailer by:

going to the rear of the second trailer and open the emergency line shut off

watch the air gauge for a drop of 30 psi

you should get out and listen for air flowing through the lines

while driving at 10 mph apply the hand valve you should stop at the same in the same distance as a single trailer driving at 5 mph

20 / 40

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

all of these answers are correct

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

brake hard after accelerating

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

21 / 40

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

truck stops and police

bridges and tunnels

traffic and road conditions

fire and flooding

22 / 40

What are the three hazard classes should NOT be loaded into a trailer that has a heater air conditioner unit?

Class 1 explosives, class 8 corrosives, and division 5 oxidizers.

None of these answers are correct.

Class 1 explosives, class 3 flammable liquids, and division 21 flammable gas.

Class 2 explosives, class 3 flammable solids, and division 21 inhalation hazard.

23 / 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

24 / 40

When fueling a placarded vehicle, someone must always be:

At the nozzle, controlling the fuel flow.

Be at the rear most corner on the vehicle.

Within 10 feet of the pump with a fire extinguisher.

At the emergency power shut off for the pump.

25 / 40

The container for the mechanism that transforms the steering column action into wheel action is:

Air brake system

Steering hoses/box

Locking pin

Steering linkage

26 / 40

When stopped on a divided highway where should your reflectors be placed?

10 feet, 100 feet, and 200 feet toward the approaching traffic

20 feet, 150 feet, and 300 feet toward the approaching traffic

30 feet, 100 feet, and 150 feet toward the approaching traffic

15 feet, 75 feet, and 150 feet toward the approaching traffic

27 / 40

A disruptive passenger:

May be thrown off the bus.

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

Is not your responsibility.

Should not be allowed on the bus.

28 / 40

At what pressure is the safety valve in the air compressor tank set to open?

125 psi

100 psi

150 psi

225 psi

29 / 40

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

Stop 15 to 50 feet before the nearest rail.

Remember to never shift gears while crossing tracks.

Proceed only when you are sure no train is coming.

All of these answers are correct.

30 / 40

Air brake systems should not lose air faster than____when testing for air leakage rates in combination vehicles before applying the brake pedal.

2 psi a minute

6 psi a minute

5 psi a minute

3 psi a minute

31 / 40

What is the best way to prevent brakes form overheating while drive down a steep grade?

use countersteering practices

drive at a speed of 5 mph below your safe speed

use the trailer brakes only

use the stab braking method

32 / 40

When should you avoid using the parking brake?

whenever you park

when the brakes are hot

when the air pressure is low

while on an incline

33 / 40

The walls that separate compartments inside the tanks and having openings at the top and bottom are called:

Layers

Bulktears

Baffles

Free walls

34 / 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 should not be done

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

35 / 40

What is the most important reason for doing a school bus inspection?

For safety required by federal, state, and local laws.

To check for flat tires.

To give the mechanic something to do.

To assist the school principal with their report.

36 / 40

The average person requires how many hours of sleep per 24 hour period?

8 or 9

5 or 6

7 or 8

6 or 7

37 / 40

Which of the following is a clue another driver is impaired:

Open window in warm weather.

Exiting the interstate when there's no gas station visible.

All of these answers are correct.

Stopping at a green light, or waiting too long at a stop.

38 / 40

A leak rate for a straight truck or bus air brake system should not exceed _____psi per minute when the engine is off and the brakes are released.

39 / 40

When this item is missing or loose, movement may occur between the fifth wheel assembly and the frame.

Locking jaw

Locking pins

Lug nuts

Tandem release arm

40 / 40

When transporting both hazardous and non hazardous materials, your bills must:

Identify the materials by the letter x or rq in the hm column.

Describe the hazardous materials first.

Have the hazardous materials highlighted.

Any one of the above.

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