An Anti-Lock Braking System (ABS) helps prevent wheel lockup during hard braking. If ABS detects impending lockup, it reduces braking pressure to a safe level.

It prevents a vehicle's wheels from locking up.

It allows a vehicle's wheels to lock up.

It prevents a vehicle's wheels from locking up.

It makes turning a vehicle easier.

On newer vehicles, the trailer air supply control is an eight-sided red knob. It's used to control the tractor protection valve.

It is a triangular yellow knob.

In comparison to driving a single vehicle, you should maintain an extended following distance when driving a combination rig. Combinations require longer stopping distances than smaller vehicles.

Longer than when driving a single vehicle.

Shorter than when driving a single vehicle.

About the same as when driving a single vehicle.

Longer than when driving a single vehicle.

When driving a tractor-trailer combination equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would if operating a vehicle without ABS.

Brake as you would when driving a vehicle without ABS.

Not depress the brakes as much as you would when driving a vehicle without ABS.

Use extra braking force to ensure the ABS kicks in.

Brake as you would when driving a vehicle without ABS.

Try to not brakes as often as you would when driving a vehicle without ABS.

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.

The tractor protection valve will close.

The service brakes will activate.

The tractor protection valve will close.

The rear trailer will detach from the combination.

Before a trip, ensure that air in the air brake system reaches all trailers. Do this by waiting for air pressure to build, then sending air to both the emergency and service lines and opening the shut-off valves on the rear of the last trailer. If air escapes from the shut-off valves in the rear of the combination, the air is being supplied to the entire vehicle.

Opening the rear shut-off valves and listening for escaping air.

Closing the rear shut-off valves and listening for escaping air.

Disconnecting air supply lines and listening for escaping air.

Rolling each trailer down a hill and testing the brakes.

Combination Vehicles Practice Test | Wyoming 2025 #1

Train for FREE online with our Wyoming 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 WY combination license in 2025, 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

Combination Vehicles Practice Test | Wyoming 2025 #1

1 . What does an Anti-Lock Braking System (ABS) do?

2 . What does the trailer air supply control look like?

3 . When driving a combination rig, following distance should be:

4 . When driving a trailer with ABS, you should:

5 . Using the trailer hand brake while experiencing a trailer jackknife will:

6 . If the emergency air line loses pressure:

7 . Before a drive, ensure that air flows to all trailers by:

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