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 two, three or four possible answer choices. Test questions come from the Nebraska 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. What is another name for the service line?

The control line

The utility line

The open line

The parallel line

The trailer service air line may also be referred to as the control line or signal line.

2. When coupling a trailer:

Make sure to couple the proper glad hands.

Glad hands can be connected to any other glad hands.

Only one set of glad hands should be connected.

When coupling, make sure you couple matching glad hands. They are often color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.

3. Before driving a vehicle with a dual air brake system, you must wait for the air compressor to build a minimum of ____ in both the primary and secondary systems.

25 psi

50 psi

75 psi

100 psi

Before driving a vehicle with a dual air brake system, you should wait for the air compressor to build up at least 100 psi in both the primary and secondary systems.

4. When you need to stop in an emergency, you should:

Lock the wheels and skid to a stop.

Stop in a way that keeps your vehicle in a straight line.

Stop in a way that turns your vehicle.

Expect your vehicle to slow down more quickly than usual.

If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle traveling in a straight line while still allowing you to turn, if necessary.

5. A broken exhaust system:

Can allow poisonous fumes to enter the cabin.

Does not cause problems.

Should not be a concern.

A broken exhaust system can let poisonous fumes into a vehicle's cab or sleeper berth. Be sure to inspect your exhaust system for any loose, broken, or missing parts.

6. What is the average driver’s reaction time?

1/16 of a second

1/8 of a second

3/4 of a second

The average driver has a reaction time between three-quarters of a second and one second. At 55 mph, this corresponds to a distance of 61 feet traveled.

7. Backing with a trailer is dangerous because:

It is difficult for the driver to see behind the trailer.

There may be extra weight in the front of the vehicle.

Cargo may fall out of the trailer.

Trailers are not made to be driven in reverse.

Backing is always dangerous because it is impossible to see everything that is behind your vehicle. Only drive in reverse if it is absolutely necessary.

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