Combination Vehicles Practice Test | Arizona 2026 #2

Train for FREE online with our Arizona CDL combination vehicle test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a AZ combination license in 2026, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements for issuing a combination license may vary from state to state.

Number of Question 20

Passing Score 16

Number of Tests 20

1 . If the emergency air line loses pressure:

The service brakes will activate.

The tractor protection valve will close.

The rear trailer will detach from the combination.

The tractor protection valve keeps air in the trailer's braking system should the trailer break away or develop a leak. A loss of air pressure in the emergency line will cause the tractor protection valve to open and the emergency trailer brakes to activate.

2 . The tractor protection valve:

Ensures that oil adequately lubricates the engine.

Protects the tractor from exceeding a set speed.

Keeps air in the truck braking system if the trailer develops a leak.

A tractor protection valve keeps air in a tractor or truck air brake system should the trailer break away or develop a bad leak. The valve will close automatically if the pressure drops to an unsafe level.

3 . Fully-loaded rigs:

Usually are very responsive to steering.

Are more likely to roll over than empty rigs.

Can stop quickly.

Fully-loaded rigs are more vulnerable to rolling over than empty rigs because the weight of the cargo gives the vehicles higher centers of gravity.

4 . Older trailers are not equipped with spring brakes. This means that if the air supply for a vehicle's air braking system leaks away:

The trailer will stop normally.

The trailer will not have brakes.

The trailer will speed up.

Older trailers do not have spring brakes. This means that if the air supply in an older trailer's air tank has leaked away, there will be no working brakes connected to the trailer and its wheels will turn freely.

5 . If a parked trailer does not have spring brakes, you should keep the trailer from moving by:

Having the vehicle parked against a wall or other vehicle.

Using chock blocks.

Parking on a slight incline.

If a parked trailer does not have spring brakes, wheel chocks should be used to prevent it from moving.

6 . When coupling a trailer, you should:

Couple together the proper glad hands.

Couple glad hands with any other glad hands.

Leave one pair of glad hand loose.

When coupling air brake hoses, you should make sure the proper pairs of gland hands are connected. They are sometimes color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.

7 . When coupling a trailer:

Make sure to couple the proper glad hands.

Glad hands can be connected to any other glad hands.

Only one set of glad hands should be connected.

When coupling, make sure you couple matching glad hands. They are often color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.

Study tip:

Reduce your study time from hours to minutes with a DMV exam “Cheat Sheet”

99.2% of people who use the cheat sheet pass the FIRST TIME

Click Here
Full Cheat Sheet

99.2%

99.2% of people who use the cheat sheet pass the FIRST TIME

2026 Arizona | Frequently Asked Questions

In Arizona, to secure a CDL Doubles/Triples endorsement, you must first have a valid Commercial Driver's License (CDL). Then, you'll need to pass the Doubles/Triples endorsement knowledge test administered by the Arizona Department of Transportation. Studying the CDL manual and taking practice tests can help prepare for this exam.

To obtain a CDL Doubles/Triples license, you first need a valid Commercial Driver's License (CDL). You must then pass the Doubles/Triples endorsement knowledge test. Preparation can include studying the CDL manual, particularly sections on coupling and uncoupling and inspecting doubles and triples. Lastly, pay the required fees to the Arizona Department of Transportation.

While Arizona doesn't mandate specific training for a CDL Doubles/Triples endorsement, it's beneficial to have practical experience or training. Understanding how to handle these larger, more complex vehicles safely is crucial. You'll need to pass the Doubles/Triples Endorsement Test, so studying the CDL manual and possibly taking a preparation course could be helpful.

Yes, to obtain a CDL Doubles/Triples endorsement in Arizona, you must pass the Doubles/Triples endorsement knowledge test. This test assesses your understanding of specific rules and safety standards for operating these vehicles. Studying the CDL manual and taking practice tests can help you prepare for this exam.

The CDL Doubles/Triples endorsement test in Arizona is primarily a knowledge test, focusing on understanding safety rules and procedures rather than specific maneuvers. Key topics include coupling and uncoupling, inspecting doubles and triples, and managing the vehicles' size and weight. However, practical skills like maneuvering and controlling these large vehicles are crucial for safe operation on the road.

No, it is not permissible to operate double/triple trailers without a valid CDL Doubles/Triples endorsement in Arizona. Driving such vehicles without the proper endorsement is illegal and can result in serious penalties, including fines and suspension or revocation of your commercial driver's license.

The CDL Doubles/Triples endorsement can be added to your existing commercial driver's license. You do not need to initiate a new application for a separate license. However, you will need to pass the Doubles/Triples endorsement knowledge test and pay the appropriate fees to have this endorsement added to your CDL.

Yes, drivers with a CDL Doubles/Triples endorsement must adhere to specific limitations. For example, the maximum length for a trailer in a double/triple combination is 28.5 feet. Furthermore, drivers are restricted to hauling doubles/triples on designated highways and during specific hours of the day, as determined by state and federal regulations.

The maximum length for a trailer in a double/triple combination is 28.5 feet. In terms of weight, federal law allows a maximum gross vehicle weight of 80,000 pounds, but this can be influenced by the number and spacing of axles. However, states can set their own restrictions, so it's advisable to check with local authorities.

Yes, drivers with a CDL Doubles/Triples endorsement must follow specific safety regulations. These include maintaining a safe following distance, not exceeding speed limits, ensuring proper coupling and uncoupling of trailers, and conducting pre-trip inspections. Additionally, drivers must understand the high rollover risk associated with these trailers and the effects of "crack-the-whip" scenarios.