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 need to correctly answer a minimum of 16 questions to pass. The Combination test is not a replacement for the Double/Triple endorsement test.

Number of Question 20

Passing Score 16

1. Combination vehicles:

Often have taller trailers than single commercial vehicles.

Are usually lighter than single commercial vehicles.

Require more skill to drive than single commercial vehicles.

Driving combination vehicles requires more skill than driving single commercial vehicles. Combinations are generally longer, generally heavier, and are more vulnerable to rollover.

2. The emergency air line supplies air to the:

Relay valves.

Trailer air tanks.

Signal line.

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

3. What is the tractor protection valve?

A valve that keeps air in the brake system should a bad leak occur

A valve that prevents the trailer from being accidentally released

A valve that prevents the vehicle from going too fast

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.

4. Combination vehicles are usually:

Easier to drive than single commercial vehicles.

Lighter than single commercial vehicles.

More difficult to drive than single commercial vehicles.

Driving combination vehicles requires more skill than driving single commercial vehicles. Combinations are generally longer, generally heavier, and are more vulnerable to rollover.

5. The best way to recognize that your trailer has begun to skid is by:

Seeing other drivers' faces.

Seeing it in your mirrors.

Feeling it.

Listening to the radio.

The earliest and best way to recognize the beginnings of a trailer skid is by seeing the trailer veer off-course in your mirrors.

6. To prevent a trailer from rolling over, you should:

Speed up when nearing a corner.

Make sudden steering moves.

Take on-ramps faster than the posted speed limit.

Drive slowly around corners.

To reduce the risk of a rollover when driving a combination vehicle, you should keep the weight of the cargo as low to the ground as possible and drive slowly around turns.

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

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.

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.

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