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

When driving tank vehicles you should:

Decrease your speed before entering a curve and then accelerate through it.

None of the answers listed.

Maintain the posted speed limit as you enter the curve.

Come to a stop before entering a curve and then accelerate through it.

2 / 40

What should you hear when you have the hand valve on and are testing the trailer brakes by opening the service air line at the back of the trailer?

the emergency line valve to release air

air leaving the open valve

the engine brake to kick on

the service brakes more to a fully applied position

3 / 40

You must first______to supply air to the trailer.

push in the tractor protection valve

cross the air lines to check for the presence of leaks

turn off the engine so you can hear the brakes

pull out the tractor protection valve

4 / 40

You must not allow riders to stand:

Between the wheel wells.

Within two feet of an emergency exit.

In front of the standee line.

Within two feet of any window.

5 / 40

You should follow behind other vehicles ______when traveling under 40 mph.

at a distance of 1 seconds for every 10 feet of your vehicle length

at a distance of 1 second for every 5 feet of your vehicle length

as close as possible so other drivers won't cut in front of you

at a distance of 1 second for every 15 feet of your vehicle length

6 / 40

Make sure____when the front trailer supports are up and the trailer is sitting on the tractor.

neither of the answers listed

both of the answers listed

there is enough space for clearance between the landing gear and the tractor frame

there is enough space for clearance between the nose of the trailer and the tops of the tractor tires

7 / 40

Animals and human foodstuffs should not be loaded in the same vehicle with?

Flammable liquids

Flammable gases

Poisons

Explosives

8 / 40

When inspecting the_____you pump the pedals 3 times and then hold it down for 5 seconds feeling for no movement to occur.

engine brakes

all answers listed

hydraulic brakes

emergency brakes

9 / 40

You should adjust all the outside left and right side convex mirrors to see:

The entire area to the rear of the mirror along the side of the bus.

The right and left front tires touching the ground.

The children's exit path out of the main bus door.

200 feet behind the bus.

10 / 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.

responsible, papers

licensed, manifest

trucking, uniform hazardous waste manifest

registered, uniform hazardous waste manifest

11 / 40

What is the first thing to do if your vehicle catches fire while driving?

open the door and jump out of the vehicle

find a service station to pull into

open the hood and let the flames die down

pull off the road and park in an open area

12 / 40

The interlock system for the brake and accelerator on a transit coach may be used:

To replace the rear door emergency buzzer.

As a safety feature when the exit door is open.

To replace the parking brake.

All of these answers are correct.

13 / 40

Which of the following statements is FALSE?

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

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

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

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

14 / 40

Which seats must have a seat belt:

All of these answers are correct.

Women and children seats.

The driver's seat.

Senior citizen seats.

15 / 40

With the controlled braking method, you _____?

apply the brakes all the way until the wheels lock up, release the brakes and apply them again when the wheels start to roll again

repeatedly tap the brakes as fast as you can

apply the brakes as hard as you can without locking the wheels

lightly apply braking pressure

16 / 40

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

1 to 2 inches

it is dependent on the load you are carrying

1/4 to 1/2 of an inch

zero

17 / 40

Which trailer should be the first one after the tractor?

the trailer that is the shortest in length

the trailer that weighs the most

the trailer that weighs the least

none of the answers listed

18 / 40

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

federal and state laws require you to inspect your vehicle

to save you money by preventing costly repairs

safety for yourself and other road users

to insure that you will achieve the best gas mileage

19 / 40

You should check that the following makes an audible noise:

Engine brakes

Radio system

Air leaks

Electric or air horn

20 / 40

The crack-the-whip effect is more likely to cause the front trailer to tip over.

trailers never tip

true

false

there is an equal chance for trailers to tip

21 / 40

Why is it dangerous to unlock the pintle hook with the dolly still under the rear trailer?

the kingpin may snap in half

the dolly tow bar may fly up

the spring brakes may release

the fifth wheel may be misaligned

22 / 40

You should check the_____when loading small tanks equipped with bulkheads.

fuel to air ratio

distribution of the weight

percentage of water

expansion rate

23 / 40

Why does it take special skills to haul a tank vehicle?

All of the answers listed.

There is a high center of gravity.

The weight of the load is high up off the road.

It is top heavy.

24 / 40

Which of the following is NOT an acceptable type of marking for hazardous materials?

Un marks

Descriptive name in roman print

Identification number

Name in italics

25 / 40

Make sure that____when the front trailer supports are up and the trailer is resting on the tractor.

there is enough clearance between the landing gear and the tractor frame

the safety latch is in the open position

the kingpin has been removed

there is enough clearance between the lower and upper fifth wheel

26 / 40

You should_____when the low pressure warning is activated:

come to a safe stop while you still have control of the brakes

wait until the air brakes kick in automatically

pump the brake pedal to come to a stop immediately

maintain highway speed and keep an eye on your air pressure gauge

27 / 40

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

the trailer longest in length

the trailers shortest in length

the trailer with the heaviest load

the trailer with the smallest road

28 / 40

Buses may NOT have recapped or regrooved tires:

On front wheels.

On the outside rear wheels.

Anywhere except on the front wheels.

When it's been raining.

29 / 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

protect the area

care for the injured

notify authorities

30 / 40

Double and triple trailers should be driven with care to avoid a rollover or jacknife.

true

only on downgrades

false

only in ideal conditions

31 / 40

A portable tank differs from a cargo tank in that ______.

cargo tanks are bulk containers, which are not permanently attached to a vehicle

portable tanks are bulk containers, which are not permanently attached to a vehicle

none of these answers are correct

portable tanks are bulk containers, which are permanently attached to a vehicle

32 / 40

The compressor is connected to the engine via _____?

v-belt or gears

stag gears

lines

r-belt

33 / 40

When accelerating:

speed up smoothly and gradually and avoid jerking

always use the parking brake to slow down

do not engage the clutch before you take your foot off the brake

"hammer down" when your wheels start to spin

34 / 40

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

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

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.

35 / 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

36 / 40

Select the true statement in regards to brake drums:

All of these answers are correct.

They are bolted to the wheels.

Hold the brake linings and shoes.

They are located at both ends of the axles of the vehicle.

37 / 40

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

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

check for yellow abs malfunction lamps on the instrument panel

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

all of these answers are correct

38 / 40

Upon what does the amount of liquid you can carry in a load depend?

All of the answers listed.

The legal weight limits.

The amount of expansion that will occur.

The weight of it.

39 / 40

Select the item that is not checked in the engine compartment:

The level of the oil

The oil pressure

The power steering fluid

The coolant level

40 / 40

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

the center of the kingpin is past the locking jaw

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

the kingpin is over the fifth wheel

all answers listed

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