Instructions

Double

This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice.. Read More

This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice questions. To pass, the applicant must answer at least 16 questions correctly. Test questions come from the Commonwealth of Pennsylvania Commercial Driver’s Manual. Questions come from chapter covering: Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.

Number of Question 20

Passing Score 16

1. What is another name for the service line?

Control line

Exchange line

Surplus line

Parallel line

The service line, also called the control line or signal line, carries air to the trailer brakes and is controlled by the foot brake or trailer hand brake.

2. Eating while driving:

Is a good way to maximize time.

Is encouraged on long trips.

Creates a distraction for the driver.

Is mandatory so cargo is not left unsupervised.

To reduce the chances of driving distracted, you should avoid eating, drinking, or smoking while driving. Anything that diverts attention from the task of driving is a distraction.

3. Low underneath clearance can cause difficulties when driving:

Over railroad crossings.

On gravel roads.

Around corners.

At the posted speed limit.

Railroad-highway crossings may be difficult to cross if you are pulling a trailer with low underneath clearance. In particular, both low-slung units and single-axle tractors pulling long trailers are especially challenging to drive over raised crossings.

4. Push in the trailer air supply control to:

Activate the emergency brakes.

Deactivate the air brakes.

Sound the horn.

Supply the trailer with air.

Push in the trailer air supply control to supply the trailer with air. Pull out the trailer air supply control to turn off the air supply and activate the emergency brakes.

5. Cargo inside a trailer:

Does not need to be secured.

Should be stacked no more than three feet high.

Should be secured to prevent movement.

Should be loaded with the heaviest items on top of lighter items.

Cargo needs to be secured appropriately to prevent it from moving in transit. Cargo should be arranged to keep the vehicle's center of gravity low and well-distributed.

6. What happens when the wheels of a trailer lock up?

The trailer will usually continue to move in a straight line.

The trailer will disengage.

The trailer will likely swing around.

The trailer will stop.

A trailer tends to swing around, potentially resulting in a trailer jackknife, if its wheels lock up.

7. A vehicle equipped with an Anti-Lock Braking System (ABS) uses a ____ light to warn that the system is not working properly.

Green

Yellow

Orange

White

Anti-Lock Braking System (ABS) malfunction lamps are usually yellow. Even if the ABS isn't working properly, a driver will still have access to the vehicle's usual braking functions.

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