# Double

This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice..

This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice questions. To pass, the applicant must answer at least 16 questions correctly. Each question has three possible answer choices. Test questions come from the Iowa Commercial Driver License Manual. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.

Number of Question
Passing Score

### 8. On slippery roads, you should:

Explanation
On a slippery road, you must adjust your driving speed to fit conditions. Because it will take longer for your vehicle to stop on a slippery road than on a dry road, you should increase your following distance when conditions are slippery. Avoid driving in a way that requires you to change speeds frequently.

### 9. When are people usually the least alert?

Explanation
Most drivers are the least alert at night, especially after midnight. Therefore, crashes due to fatigued driving are more likely at night than any other time of day.

### 10. To make a stop in a vehicle equipped with air brakes, the driver should:

Explanation
To make a normal stop in a vehicle that is equipped with air brakes, you should simply press the brake pedal down.

### 11. In a double or triple combination, the ____ trailer should be directly behind the cab.

Explanation
When positioning trailers in a combination, the most heavily-loaded trailer should be the closest to the tractor. The lightest trailer should be positioned in the rear.

### 12. A slack adjuster should move no more than ____ from where it is attached to the push rod.

Explanation
Before a trip, you should check each slack adjuster after parking, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure that they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.

### 13. Using an Anti-Lock Braking System (ABS):

Explanation
An Anti-Lock Braking System (ABS) helps to provide additional control during hard braking, but does not necessarily shorten a vehicle's stopping distance.

### 14. A combination vehicle has ____ air line(s).

Explanation
Every combination vehicle has two air lines: the service line and the emergency line.

To obtain a CDL Doubles/Triples endorsement in Iowa, you need to follow these steps:

1. Obtain a commercial learner's permit (CLP): You can obtain a CLP by passing the written tests for general knowledge and combination vehicles. You must also pass a vision test and provide proof of your identity and residency.

2. Study for the Doubles/Triples endorsement: You can obtain study materials from the Iowa Department of Transportation (DOT) or from commercial driving schools.

3. Schedule a skills test: Once you feel confident in your knowledge of the Doubles/Triples endorsement, you can schedule a skills test with your local DOT office. During this test, you will be required to demonstrate your ability to safely operate a vehicle with double or triple trailers attached.

4. Pass the skills test: If you pass the skills test, you will be issued a CDL with the Doubles/Triples endorsement.

Note that you must already have a valid CDL to obtain the Doubles/Triples endorsement. Also, keep in mind that there may be additional requirements or restrictions for operating double or triple trailers in Iowa, so make sure to familiarize yourself with these before hitting the road.
To get a CDL Doubles/Triples license in Iowa, you must meet the following requirements:

1. Be at least 18 years old: You must be at least 18 years old to obtain a CDL Doubles/Triples license, but you will be restricted to intrastate driving only.

2. Have a valid Iowa CDL: You must already have a valid Iowa CDL before you can obtain the Doubles/Triples endorsement.

3. Pass the written test: You must pass the written test for the Doubles/Triples endorsement. This test will cover topics such as coupling and uncoupling, inspecting a double/triple combination, and safe driving practices for double/triple vehicles.

4. Pass the skills test: You must also pass a skills test that demonstrates your ability to safely operate a double/triple combination vehicle.

5. Pay the fee: There is a fee associated with obtaining the Doubles/Triples endorsement, and you will need to pay this fee at your local DOT office when you apply.

In addition to these requirements, there may be other restrictions or requirements for operating double/triple combination vehicles in Iowa, so make sure to familiarize yourself with these before hitting the road.
While the Iowa DOT does not generally require specific experience or training to obtain a CDL Doubles/Triples endorsement, it is highly recommended that you receive training before attempting to operate a double or triple combination vehicle. This is because these types of vehicles require a higher level of skill and knowledge than standard commercial vehicles.

You may want to consider attending a commercial driving school or taking a training course specifically designed for Doubles/Triples endorsement. These courses will provide you with the knowledge and skills necessary to safely operate these types of vehicles and will also give you valuable hands-on experience.

Additionally, some carriers may require that you have a certain amount of experience driving commercial vehicles before they will allow you to operate a double or triple combination vehicle. It's always a good idea to check with your employer or prospective employer about their specific requirements before pursuing the Doubles/Triples endorsement.
Yes, to obtain a CDL Doubles/Triples endorsement in Iowa, you will need to pass an additional written test specifically for this endorsement. This test will cover topics such as:

1. Coupling and uncoupling procedures for double/triple combination vehicles
2. Inspecting double/triple combination vehicles for safety
3. Safe driving practices for double/triple combination vehicles
4. Special rules and regulations that apply to double/triple combination vehicles

The Iowa DOT provides a study guide specifically for the Doubles/Triples endorsement that you can use to prepare for the test. It's important to study this guide thoroughly and take practice tests to ensure that you have a good understanding of the material before taking the actual test.

In addition to the written test, you will also need to pass a skills test that demonstrates your ability to safely operate a double/triple combination vehicle. This skills test will include tasks such as coupling and uncoupling the vehicle, backing up, and maneuvering in tight spaces.

Overall, obtaining a CDL Doubles/Triples endorsement requires a higher level of knowledge and skill than a standard commercial driver's license, so it's important to take your training and preparation seriously in order to ensure that you are fully qualified and able to operate these types of vehicles safely.
To obtain a CDL Doubles/Triples endorsement in Iowa, you will need to pass a skills test that demonstrates your ability to safely operate a double/triple combination vehicle. The skills test will include the following maneuvers:

1. Pre-trip inspection: You will need to demonstrate your ability to perform a thorough pre-trip inspection of your double/triple combination vehicle, checking for any safety issues or mechanical problems.

2. Coupling and uncoupling: You will need to demonstrate your ability to properly couple and uncouple the double/triple combination vehicle, including connecting and disconnecting the air lines, electrical cables, and safety chains.

3. Straight line backing: You will need to demonstrate your ability to back up the double/triple combination vehicle in a straight line for a distance of approximately 100 feet.

4. Off-set backing: You will need to demonstrate your ability to back up the double/triple combination vehicle into a space that is offset from your starting position.

5. Alley dock backing: You will need to demonstrate your ability to back up the double/triple combination vehicle into an alley dock, which simulates backing into a loading dock or other tight space.

6. On-road driving: You will need to demonstrate your ability to safely operate the double/triple combination vehicle on public roads, including turning, merging, changing lanes, and driving in traffic.

It's important to note that the specific maneuvers and requirements for the CDL Doubles/Triples endorsement skills test may vary depending on the testing location and examiner. Be sure to check with your testing location or examiner for specific details on what you can expect during the skills test.
No, in Iowa, you are required to have a CDL Doubles/Triples endorsement in order to operate a double/triple trailer combination.

A CDL with a Doubles/Triples endorsement is required if the combined weight of the two trailers is over 26,000 pounds. Additionally, if the weight of any single trailer exceeds 10,000 pounds, a CDL with a Doubles/Triples endorsement is also required.

It's important to note that driving a double/triple trailer combination requires additional skill and knowledge compared to driving a single commercial vehicle. The Doubles/Triples endorsement requires an additional written test and skills test to prove that you have the necessary skills and knowledge to safely operate these types of vehicles.

Operating a double/triple trailer combination without the proper endorsement can result in fines, penalties, and even license suspension or revocation. It's important to follow all rules and regulations related to commercial driving in order to keep yourself and others on the road safe.
In Iowa, you can add the CDL Doubles/Triples endorsement to your existing CDL license by passing the required written and skills tests. You do not need to apply for a new license.

To add the Doubles/Triples endorsement, you will need to pass a written test covering the specific knowledge required for operating double/triple trailer combinations. Once you pass the written test, you will need to pass a skills test that includes maneuvers specific to operating double/triple trailer combinations.

After passing both tests, you will need to pay a fee and provide the necessary documentation to have the endorsement added to your CDL license. It's important to note that you must already hold a valid CDL license before applying for the Doubles/Triples endorsement.

To ensure that you are fully prepared for the written and skills tests, it's recommended that you study the Iowa Commercial Driver's Manual and practice driving a double/triple trailer combination with a qualified instructor or training program.
Yes, there are some restrictions and limitations for drivers with a CDL Doubles/Triples endorsement in Iowa. These restrictions are designed to ensure the safety of the driver and other motorists on the road.

Here are some of the key restrictions and limitations for drivers with a CDL Doubles/Triples endorsement in Iowa:

1. Vehicle Weight: The combined weight of the double/triple trailer combination must not exceed 80,000 pounds.

2. Trailer Length: The maximum length for each trailer is 28 feet.

3. Driver Age: Drivers under 21 years of age are not permitted to drive double/triple trailers.

4. Experience: Drivers must have at least two years of experience operating a commercial motor vehicle before they can apply for the Doubles/Triples endorsement.

5. Endorsement Renewal: The Doubles/Triples endorsement must be renewed every five years, and drivers may be required to retake the written and skills tests to renew their endorsement.

It's important to follow all restrictions and limitations related to operating double/triple trailer combinations in order to ensure your safety and the safety of others on the road.
In Iowa, the maximum weight limit for double/triple trailers with a CDL Doubles/Triples endorsement is 80,000 pounds. The maximum length limit for each trailer is 28 feet.

It's important to note that these weight and length limits apply to the combined weight and length of the double/triple trailer combination. If the combination exceeds these limits, it may be subject to fines and penalties.

Drivers with a CDL Doubles/Triples endorsement must also follow all other restrictions and limitations related to operating double/triple trailer combinations, including driver age requirements and experience requirements.

It's important to be familiar with all of the rules and regulations related to operating double/triple trailers if you hold a CDL Doubles/Triples endorsement, in order to ensure your safety and the safety of other motorists on the road.
Yes, there are several specific safety considerations and regulations that drivers with a CDL Doubles/Triples endorsement must follow when operating double/triple trailers. These regulations are in place to ensure the safety of the driver and other motorists on the road.

Here are some of the key safety considerations and regulations for drivers with a CDL Doubles/Triples endorsement in Iowa:

1. Vehicle Inspection: Drivers must inspect their vehicles before each trip to ensure that they are in good working condition.

2. Braking Systems: Double/triple trailers must be equipped with a braking system that meets certain requirements, including a breakaway system and an emergency air brake system.

3. Coupling and Uncoupling: Drivers must be trained in proper coupling and uncoupling procedures, and must ensure that all connections are secure before driving.

4. Speed Limits: Drivers must obey posted speed limits and adjust their speed based on road conditions, weather, and other factors.

5. Turning: Double/triple trailers require more space to turn than single trailers, so drivers must be aware of their surroundings and make wider turns when necessary.

6. Lane Changes: Drivers should avoid making sudden lane changes or abrupt movements that could cause the trailer to sway.

7. Bridge Restrictions: Double/triple trailers may not be allowed on certain bridges or overpasses due to weight restrictions.

It's important for drivers with a CDL Doubles/Triples endorsement to follow all safety regulations and guidelines when operating double/triple trailers, in order to ensure their own safety as well as the safety of other motorists on the road.