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Safely pulling double and triple trailers requires knowledge and skill. If you want to pull double or triple trailers, you must add the Doubles/Triples (T) endorsement to your Class A CDL. The Maryland doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The MD CDL doubles triples test covers the following sections of the Maryland CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this MD CDL practice test now to prepare for the actual test!
1. If there is a fire in your vehicle, do NOT:
park in an open area.
notify emergency services.
pull into a service station.
park away from buildings and other vehicles.
2. When coupling a double or triple, ________ should be attached last.
the trailer right behind the cab.
the middle trailer.
the more heavily loaded trailer.
None of the above.
3. Which of the following is a reason to cover cargo?
To contain a spill
To protect the cargo from weather
To protect people from spilled cargo
All of the above.
4. Regardless of its size, cargo should have at least ___ tie-downs.
4
2
3
1
5. Under a pressurized system, the radiator cap:
should never be hot.
should be removed when the coolant is hot.
should never be removed until the system has cooled.
should always be cool.
6. When possible, you should park:
on the shoulder.
so you will be able to pull forward when you leave.
on the roadway.
so you will have to back up when you leave.
7. When you push in the red trailer air supply knob, this will:
open the emergency line shut-off valve at the rear of the last trailer.
disconnect the electrical connector.
disconnect the air lines from the trailer.
supply air to the emergency supply lines.
8. How should you brake if your vehicle loses ABS?
Step on and off the brake pedal several times
Brake as you always have.
Stay off the Brake
Pump the brake repeatedly
9. Brake lag is:
the distance your vehicle will continue to travel, in ideal conditions, before you hit the brakes.
the time required for the air brakes to work after the brake pedal is pushed.
the amount of air pressure required to stop the vehicle.
the distance your vehicle will travel, in ideal conditions, while you are braking.
10. If you will be transporting hazardous materials that require placards, you must:
ask permission of the local transportation agency.
obtain a hazardous materials endorsement.
obtain a special transit permit.
transport the materials at night only.
 
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MD Doubles Triples CDL Test

Number of questions: 20
Correct answers to pass:16
Passing score:80%
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