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 three or four possible answer choices. Test questions come from the Mississippi Professional Driver’s Manual. Questions come from chapters covering: Driving Safely, Transporting Cargo 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
Passing Score

1. What should you do if the brake pedal does not build up pressure?

Explanation
If you lose pressure in a hydraulic brake system, one appropriate response is to shift down into a lower gear. This will help slow the vehicle.

2. When coupling, you should:

Explanation
When coupling air brake hoses, you should make sure the proper pairs of gland hands are connected. They are sometimes color-coded to help drivers avoid mistakes. Typically, blue is used for service lines and red is used for emergency lines.

3. Roads are especially slippery right after it begins to rain because:

Explanation
Roads are often especially slippery when it first begins to rain. Rainwater forms a slick film when mixed with oil and grease on the road surface that has not yet washed away.

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

Explanation
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.

5. If the coolant temperature gauge goes above the highest safe temperature, you should:

Explanation
If the coolant temperature gauge goes above the highest safe temperature, you should stop driving as soon as possible and try to figure out what is wrong. There could be an issue in your vehicle that could lead to engine failure and possibly a fire.

6. When transporting cargo, drivers must check the securement of the cargo every:

Explanation
The securement of cargo must be checked before beginning a trip, within the first 50 miles of a trip, and then again every three hours or 150 miles.

7. When loading a trailer, the heaviest cargo should be placed:

Explanation
It is important that vehicles are not top-heavy, if at all possible. A top-heavy vehicle is at an increased risk of rollover. Place the heaviest pieces of cargo underneath lighter pieces of cargo.
DMV Writen Test Logo