Vermont CDL Combination Test (VT) 2026

4.9 out of 5 (40 votes)
80% Passing score
20 Questions
4 Mistakes allowed
As a Vermonter looking to secure your Commercial Driver's License (CDL) combination vehicles endorsement, our VT practice permit test is an essential tool for your preparation. This CDL combination practice test is designed with your success in mind, providing you with a comprehensive array of multiple-choice questions that mirror those you'll encounter on the actual DMV test. By taking our Vermont permit practice test, you'll become familiar with the format and content of the real test, ensuring you are well-prepared on test day. Our learner's permit practice test covers all the key areas necessary for mastering the combination vehicle section of the CDL test. From coupling and uncoupling to pre-trip inspections, driving techniques, backing and maneuvering, and air brake systems, this Vermont CDL combination test delves into every crucial topic. The practice test consists of 20 questions, and you'll need to answer at least 16 correctly to pass. This rigorous preparation is crucial for understanding the increased stopping distances required for combination vehicles due to their greater weight, a critical aspect of maintaining safety on the road. While the DMV restricts the publication of actual test questions, our VT permit test practice is crafted to closely mimic the real DMV permit test experience. By covering identical topics and using comparable phrasing, our combination CDL test enables you to grasp the essential concepts you'll need to know. This authentic practice experience ensures that you are not only ready to pass the test but also to handle the unique challenges presented by larger, heavier vehicles in real-world scenarios. At the end of the Vermont combination vehicle test, you'll receive a detailed summary of your performance. This summary highlights the questions you answered incorrectly and provides the correct answers for learning purposes. This feedback is invaluable for identifying areas where you need further study and reinforcing your knowledge before taking the actual test. By integrating our combination CDL practice test into your study routine, you'll build the confidence and skills necessary to excel. Prepare effectively and ensure you're ready to tackle the demands of driving combination vehicles safely and efficiently on Vermont's roads.
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Sample Vermont Combination Test Questions

Question 1

During a trailer jackknife, should the trailer hand valve be used to pull the trailer back into line?

  1. A True
  2. B False

Correct answer: B – False

Do not use the trailer hand valve to straighten a jackknifing trailer. The trailer skid began because its wheels locked, and applying the trailer brakes again can continue the loss of traction. Releasing the brakes allows the trailer wheels to regain grip, after which the trailer can begin following the tractor again.

Source: Vermont Commercial Driver’s License Manual — § 6.1.5, “Prevent Trailer Skids”

Question 2

What two functions does the emergency, or supply, air line perform?

  1. A It operates the tractor parking brake and steering system
  2. B It controls only the tractor’s emergency brakes
  3. C It fills the trailer air tanks and controls the trailer emergency brakes
  4. D It supplies ventilation air to the tractor cab

Correct answer: C – It fills the trailer air tanks and controls the trailer emergency brakes

The emergency line supplies air to the trailer’s air tanks and controls its emergency brakes. A loss of pressure in this line causes the trailer emergency brakes to apply and the tractor protection valve to close. The Vermont CDL manual also calls this line the supply line and notes that it is commonly identified in red.

Source: Vermont Commercial Driver’s License Manual — § 6.2.4, “Trailer Air-lines”

Question 3

With the engine off and brakes released, what air-pressure loss is acceptable during a one-minute leakage test of a combination vehicle?

  1. A Less than 1 psi
  2. B Less than 2 psi
  3. C Less than 3 psi
  4. D Less than 4 psi

Correct answer: C – Less than 3 psi

With a fully charged system, the engine off, and the parking brakes released, a combination vehicle should lose less than three psi in one minute. This is the released-brake leakage test. Do not confuse it with the applied-brake test, under which a loss of more than four psi in one minute is excessive for a combination vehicle.

Source: Vermont Commercial Driver’s License Manual — § 5.3.3, “Step 7 Final Air Brake Check”

Question 4

How should trailer shut-off valves be positioned during normal operation of a multiple-trailer combination?

  1. A All service valves open and all supply valves closed
  2. B All service valves closed and all supply valves open
  3. C Valves between units open; service and supply valves at the rear of the last trailer closed
  4. D Valves between units closed; rear valves on the last trailer open

Correct answer: C – Valves between units open; service and supply valves at the rear of the last trailer closed

The shut-off valves between the connected units must remain open so air reaches every trailer. Both valves at the rear of the last trailer must be closed to seal the system. The Vermont CDL manual identifies these as the service and emergency, or supply, line shut-off valves.

Source: Vermont Commercial Driver’s License Manual — § 6.2.7, “Shut-off Valves”

Question 5

After supplying air to a newly connected trailer, which check helps confirm that its brakes apply and release?

  1. A Accelerate the tractor sharply
  2. B Apply and release the trailer brakes while listening for brake movement and escaping air
  3. C Watch only the outside mirrors
  4. D Turn the steering wheel from side to side

Correct answer: B – Apply and release the trailer brakes while listening for brake movement and escaping air

After air pressure reaches normal, shut off the engine and apply and release the trailer brakes. You should hear the brakes move when they apply and hear air escape when they release. The air-pressure gauge should also be watched for signs of a major loss of pressure before the vehicle is driven.

Source: Vermont Commercial Driver’s License Manual — § 6.4.1, “Coupling Tractor-Semitrailers”

Question 6

What is usually the earliest reliable sign that a trailer has begun to skid?

  1. A Tire noise from behind the tractor
  2. B A jerking feeling at the fifth wheel
  3. C The trailer moving out of line in the mirrors
  4. D A pull through the steering wheel

Correct answer: C – The trailer moving out of line in the mirrors

The earliest and best way to recognize a trailer skid is to see the trailer begin moving out of line in the mirrors. The Vermont CDL manual advises checking the mirrors whenever the brakes are applied hard. Once the trailer swings outside its lane, preventing a full jackknife becomes much more difficult.

Source: Vermont Commercial Driver’s License Manual — § 6.1.5, “Prevent Trailer Skids”

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