Free Iowa CDL Double/Triple Trailers Practice Test 2023

Do you know how to pair double or triple trailers? If you are planning to take the CDL double/triple trailer endorsement test, make sure to know it! Our Iowa CDL Practice Test has the same questions as the real exam which is based on the Iowa CDL Manual. It covers most of the subject areas on the Double/Triple Trailers Test such as pulling double and triple trailers, the risk of rollover, managing space, and special considerations when hauling multiple trailers. In addition, each question has a detailed explanation that will help you understand the concept and answer future questions about it correctly. If you don't get the pass right away, you can take this CDL practice test an unlimited number of times to make sure you learn all the questions. Let’s try our Free Iowa CDL Double/Triple Trailers Practice Test today and pass your CDL endorsement exam! Good luck and keep driving safely!

Our CDL practice tests:
Based on 2021 IA commercial driver's license manual
Full answers + detailed explanations
Perfect for first-time, renewal applicants
IA CDL Double/Triple Trailers Test format:
20 questions
16 correct answers to pass
80% passing score
List of questions
What is a modulating control valve?
Which is true when checking air flow to all trailers?
You are driving a 100-foot truck with double trailers at 30 mph. The road is dry, and visibility is good. You should keep at least ______ seconds of space ahead of you.
In terms of stability, doubles and triples are:
The braking power of the spring brakes ______.
On older vehicles, a low air pressure warning signal comes on at what psi?
Which of these statements about the handling of doubles and triples is true?
Brake drums should not have cracks longer than what length?
At 55 mph on dry pavement, the air brake lag distance is how many feet?
You are driving a set of doubles and a set of trailer wheels goes into a skid. Which of these is most likely to occur?
During normal operation, the brakes of the double/triple trailer are controlled by:
When inspecting the shut-off valves on doubles and triples, all of the following is true except:
After coupling the converter dolly to the first trailer, the pintle hook should be:
When increased application pressure to maintain the same speed becomes necessary, you should ______.
Which of the following is the most common reason brakes fade?
Why should you never leave your vehicle unattended without applying the parking brakes?
To apply the parking brakes, you should _______.
It's important that a warning signal comes on before the air pressure in the tank falls below _______.
If your vehicle has an alcohol evaporator, the evaporator's purpose is to _____.
What affects the stopping distance for air brakes?