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 Minnesota Commercial Driver’s Manual. Questions come from chapters covering: Driving Safely, 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. If a load is 10 feet long, it should be secured by at least ____ tie-down(s).

Explanation
On flatbed trailers and trailers without sides, cargo needs to be tied down. There should be at least one tie-down for every 10 feet of cargo. Regardless of the size of the cargo, at least two tie-downs must be used.

2. An example of required emergency equipment is:

Explanation
All commercial motor vehicles are required to be equipped with the proper emergency equipment. This may include spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and at least one properly charged and rated fire extinguisher.

3. If your vehicle is hydroplaning, you should:

Explanation
If your vehicle begins to hydroplane, do not apply the brakes. Instead, release the accelerator and push in the clutch. This will slow down your vehicle and help it regain traction.

4. During an inspection, slack adjusters on S-cam brakes should not move more than:

Explanation
Check each slack adjuster after parking on level ground, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.

5. During a trip, the ____ should be open.

Explanation
When starting a trip, be sure that all shut-off valves are in the open position, except for the last valves on the rear trailer. It is important that air reaches the brakes on all trailers and that it is not able to escape from the back of the vehicle.

6. When traveling down a steep downgrade:

Explanation
On a downgrade, the braking effect of the engine should be your primary method of controlling speed. Shift down to a lower gear before starting down the hill and save the brakes for additional slowing or stopping that may be required by road or traffic conditions.

7. You can confirm that a tractor protection valve is working properly by:

Explanation
You should test the tractor protection valve by allowing the air supply to properly charge, turning off the engine, then releasing air from the system by pressing the brake pedal several times. The tractor protection valve should move into its emergency position when psi drops to an unsafe level.
DMV Writen Test Logo