Instructions

Combination

All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Commercial Driver License.. Read More

All applicants who are applying for a Class A CDL should be prepared to take the Combination test. This test covers information found in Section 6 of the Commercial Driver License Manual. Section 6 provides the information needed to safely operate tractor-trailers, doubles, triples, and straight trucks with trailers. The test is made up of 20 multiple-choice questions, and applicants will have one hour to correctly answer a minimum of 16 questions. The Combination test is not a replacement for the Double/Triple endorsement test.

Number of Question 20

Passing Score 16

1. Driving a combination vehicle ____ than driving a single vehicle.

Is easier

Requires more driving skill

Is better for training

Is safer in inclement weather

Driving a combination vehicle usually requires more skill than driving a single vehicle. Combination vehicles are generally longer and heavier than single commercial vehicles.

2. Rollovers happen when drivers:

Turn too quickly.

Do not driving fast enough.

Pay attention to the road.

Drive illegally.

A rollover happens as a result of a driver taking a turn at too high a speed. Be sure to take turns and curves safely and slowly.

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

It is a square blue knob.

It is a triangular yellow knob.

It is an eight-sided red knob.

It is a circular orange knob.

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

4. Pull out the trailer air supply control to test:

The parking brake.

The trailer emergency brakes.

The trailer service brakes.

The landing gear.

Be sure to test the trailer emergency brakes before beginning a trip. After ensuring that the trailer rolls freely, you can test the emergency brakes by pulling out the trailer air supply control, or placing it in the "emergency" position. Pull forward slightly with the tractor and make sure the trailer does not move.

5. After connecting the air lines to the trailer while coupling, you should:

Supply air to the trailer.

Chock the wheels.

Inspect the fifth wheel.

Connect the electrical cord.

Correctly following the steps to couple and uncouple trailers is vital to safely operating a combination vehicle. After connecting the air lines to the trailer while coupling, you should supply air to the trailer.

6. Avoid needing to make sudden lane changes by:

Using your horn to encourage other drivers to move out of your lane.

Only driving slower than the posted speed limit.

Watching the road ahead while driving.

Pulling off the road and waiting when there is high traffic.

Making a sudden lane change can be dangerous when driving a combination vehicle. Avoid the need to make a sudden lane change by looking down the road for upcoming obstacles that will require you to change lanes.

7. The emergency air line:

Is controlled by the foot brake.

Is connected to the relay valves.

Supplies air to the trailer air tanks.

Prevents skids.

The emergency air line (also known as the supply line) has two functions. The first is to supply air to the trailer air tanks on a combination vehicle, and the second is to control the emergency brakes.

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