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. Each question has four possible answer choices. Test questions come from the Commercial Driver License Manual. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.

Number of Question 20

Passing Score 16

1. When you leave your vehicle, you should:

Apply the parking brake.

Apply the air brake.

Not apply any brake.

Leave the door open.

Always apply the parking brake when leaving your vehicle.

2. Most heavy-duty vehicles use:

Mono air brake systems.

Dual air brake systems.

Triple air brake systems.

Quadruple air brake systems.

Most heavy-duty vehicles use dual air brake systems. A dual system has two separate air brake systems with a single set of controls.

3. After a trip:

A vehicle should be placed out-of-service.

A vehicle's oil should be changed.

A vehicle's after-trip inspection should be completed.

A vehicle's battery should be disconnected.

After a trip, you may be required to perform an inspection and file a report on each vehicle that you've driven.

4. If the brakes “pull” to one side or the other when you use them, it's a sign that:

The brakes are working properly.

The brakes need to be checked.

The brakes are new.

The brakes have too much stopping power.

If your vehicle "pulls" to one side when braking, you may have brake trouble. If there is an issue with your brakes, you should fix the issue before driving. Operating an unsafe vehicle is against federal and state laws.

5. If you are driving and your trailer begins to jackknife, you should not:

Release the brakes.

Allow the trailer to straighten out.

Apply the trailer hand brake.

Allow the wheels to grip the road.

If a trailer begins to jackknife, you should release the brakes and allow the trailer wheels to regain traction with the road. Do not apply the trailer hand brake in an attempt to straighten out the rig because it will only prolong the skid. The application of brakes is what caused the wheels to lock in the first place.

6. A convex mirror is sometimes called a ____ mirror.

Bug-eye

Square

Helper

Large vehicles often have curved, convex mirrors, sometimes referred to as "fisheye," "spot," or "bug-eye" mirrors. These mirrors provide a wider view than flat mirrors. However, they also make objects seem smaller and farther away than they actually are.