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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 Louisiana doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The LA CDL doubles triples test covers the following sections of the Louisiana CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this LA CDL practice test now to prepare for the actual test!
1. How can you tell if a converter dollie has ABS?
There is a red lamp on the left side of the dolly.
There is a yellow lamp on the left side of the dolly.
There is an ABS system on the right side of the dolly.
There is an ABS plaque on the right side of the dolly.
2. Retarders:
reduce braking distance.
improve gas mileage.
reduce the danger of slipping.
help slow a vehicle, reducing the need for using brakes.
3. If you're feeling tired while driving you should:
eat something.
increase your speed to get to your destination quicker.
drink coffee.
stop driving and get some rest.
4. As you approach off ramps and on ramps, remember:
to slow down  before you get on the curved part of an off ramp or on ramp.
that the posted speed limit may be safe for automobiles, but may not be safe for larger vehicles.
that braking and turning at the same time can be a dangerous.
All of the above.
5. If your ABS malfunctions:
the parking brakes will not work.
you still have normal brake functions.
you should immediately come to a complete stop.
the service brake will not work.
6. The trailer hand valve should be used:
to check that the fire extinguisher is charged.
to test the trailer brakes.
to check that the trailer emergency brakes are on.
to check that the trailer is locked onto the tractor.
7. When should you turn the retarder off?
when your vehicle has a high center of gravity.
when the road is slippery.
when the cargo is prone to shifting.
when the cargo is heavy.
8. Your vehicle has air brakes. To stop, you should:
push the brake pedal down.
pump the brake pedal 3 times.
release the accelerator, push in the clutch, and shift to Neutral at the same time.
pull the parking brake control knob out.
9. ABS helps you:
brake harder.
stop faster.
drive faster.
None of the above.
10. If your vehicle is equipped with air brakes, loss of air pressure in the emergency line will cause:
the vehicle to slide back and forth.
the trailer emergency brakes to come on.
the springs to put on the brakes.
the trailer supply valve to open.
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LA CDL Doubles Test

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