CDL DOUBLES TRIPLES PRACTICE TEST IOWA

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Safely pulling double and triple trailers requires knowledge and skill. If you want to pull double or triple trailers, you must add the Doubles/Triples (T) endorsement to your Class A CDL. The Iowa doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The IA CDL doubles triples test covers the following sections of the Iowa CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this IA CDL practice test now to prepare for the actual test!
1. You should be especially alert for drunk drivers:
late at night.
in the morning.
around shopping areas.
2. When you push in the red trailer air supply knob, this will:
open the emergency line shut-off valve at the rear of the last trailer.
supply air to the emergency supply lines.
disconnect the air lines from the trailer.
3. In your mirror, you see a car approaching from the rear. The next time you check your mirror, you don't see the car. If you wish to change lanes, you should:
wait until you are sure the car isn't in your blind spot.
assume the car left the roadway and change lanes as normal.
ease into the other lane slowly so the other car can get out of the way.
4. If you're feeling tired while driving you should:
eat something.
drink coffee.
stop driving and get some rest.
5. While crossing railroad tracks, you should:
shift up.
not shift gears.
shift down.
6. The parking brake:
should be used when driving in bad weather.
should be used when you need to apply the brakes firmly.
should be used whenever you park.
7. How can you tell if a converter dollie has ABS?
There is an ABS plaque on the right side of the dolly.
There is a red lamp on the left side of the dolly.
There is a yellow lamp on the left side of the dolly.
8. Radial and bias-ply tires:
should be used together.
should be used together only when driving in packed snow.
should not be used together.
9. Air brakes use ________ to make the brakes work.
compressed gas cylinders
compressed gases
compressed air
10. Hanging meat in a refrigerated truck:
can be a very unstable load.
should never be transported.
will not affect safe driving ability.
 
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Frequently Asked Questions

If you are under 18, you must follow the Iowa Graduated Driver Licensing (GDL) Program. Here are the three phases of the program and the corresponding ages:

  1. Instruction permit? you must be 14 years old. After holding the permit for six months without traffic violation, you can also apply for a minor school license at 14 ½ years old. This special permit is optional and allows you to drive to school or to school activities within a 50-mile distance from your home.
  2. Intermediate license ? you must be 16 years old and have held an instruction permit for 12 months.
  3. Full license ? you must be at least 17 and have held an intermediate license for 12 months. Alternatively, you can directly obtain a class C driver's license at 18.
You have two options:

  1. You can schedule an appointment to take the exam at a service center. Simply locate the nearest Iowa DMV branch and choose your preferred date and time.
  2. If you are a minor between 14 and 17, you can take the knowledge test at a participating school/agency or at home using an electronic device connected to the internet. Once your parent completes and submits the application to Proctor Knowledge Exam Form, you’ll receive an email with instructions for proceeding. After successfully passing the exam, make an appointment to obtain the permit.

You can schedule an appointment for either option on the Iowa Department of Transportation website.

When applying for a driver’s license for the first time, you must bring the following documents:

  • Proof of identity, date of birth, and lawful status (e.g, U.S. passport, birth certificate, certificate of naturalization). If your legal name differs from your identity document, provide proof of the change, such as a certified marriage certificate, court order documents, or ID card.
  • Proof of Social Security Number (SSN).
  • Two proofs of Iowa residency and current residential address (e.g, Iowa voter registration card, utility bill, credit card statement…). If you are under 18 and unmarried, your parent/guardian must sign the Written Consent form to establish your residence. Additionally, provide a second printed document displaying your current name and current Iowa residential address, such as a report card or medical form.

You can use the online checklist provided by the Iowa DOT to ensure you have all the required documents. 

The DMV written test in Iowa is not exclusively provided in English but is offered in various languages, including Albanian, Arabic, Bosnian, Burmese, Cambodian, Chinese, French, German, Greek, Hebrew, Hmong, Italian, Korean, Laotian, Polish, Portuguese, Russian, Somali, Spanish, and Vietnamese. If you need an interpreter for a language not provided, you have to schedule an appointment.
To get ready for the DMV written test, start by reading the Iowa Driver License Manual. This manual has all the info you need to study for the exam: traffic signs, road rules, and safe driving practices. Then, check what you've learned with our free practice tests!

For new drivers in Iowa, various restrictions apply:

Instruction Permit
  • You cannot drive alone and you must be accompanied by a driver education instructor, a licensed parent/guardian, a licensed member of your family who is at least 21, or a licensed adult who is at least 25 (with parental permission if you are a minor).

Minor School License
  • You can't drive alone, except for school activities between 5 a.m. and 10 p.m.

Intermediate License
  • You cannot drive alone between 12:30 a.m. and 5 a.m., unless a parent/guardian completes a Waiver of Intermediate Driver’s License Hour Restriction form.
  • For the first six months, you cannot transport more than one minor without supervision, except for siblings.

The instruction permit is valid for four years. During this period, complete the 20 hours of supervised driving and after holding the permit for 12 months and maintaining a clean driving record for 6 months, you can apply for the intermediate license.
If you fail your DMV written test in Iowa, you have to wait at least one business day before retaking it. Before trying again, focus on the sections of the manual you have overlooked and consider signing up for DMV Premium to access additional practice tests!

IA CDL Doubles Triples Test

Number of questions: 20
Correct answers to pass:16
Passing score:80%
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