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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 Oregon doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The OR CDL doubles triples test covers the following sections of the Oregon CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this OR CDL practice test now to prepare for the actual test! Important: Triple trailers are not legal in Oregon.
1. To warn drivers behind you when you see you'll need to slow down, you should:
sound your horn.
flash the brake lights.
turn off your lights.
use your headlights.
2. If your brakes fail on a steep mountain downgrade, you should:
slow down until your vehicle comes to a complete stop.
set the parking brake and park in an open area.
stay on the road and keep looking for the next available escape ramp.
decide what to do as soon as you know your brakes do not work.
3. To make the brakes work, air brakes use:
hydraulic air.
compressed air.
carbon monoxide.
4. Which of these describes the proper braking technique when driving on a long and steep downgrade?
Release the brakes until your speed is 5 mph above your safe speed, then apply the brakes. When your speed has decreased to your safe speed, repeat the previous steps.
Apply the brakes. When your speed has been reduced to 5 mph below your safe speed, release the brakes. When your speed has increased to your safe speed, repeat the previous steps.
Apply the brakes until your speed has been reduced to 5 mph, then release the brakes. When your speed has increased to your safe speed, repeat the previous steps.
All of the above.
5. Before driving a vehicle with a dual brake brake system, the driver should:
wait at least 5 minutes before driving.
allow time for the air compressor to build up a minimum of 100 psi pressure in both the primary and secondary systems.
wait at least 10 minutes before driving.
pump the brake pedal 10 times to build pressure.
6. If you must stop on a one-way or divided highway, you should place warning devices _______ toward the approaching traffic.
5, 50 and 500 feet
10, 100 and 200 feet
5, 25 and 50 feet
3, 15 and 45 feet
7. When the wheels of a trailer lock up, which of the following is most likely to occur?
The trailer will tend to swing around (trailer jackknife).
The trailer will tend to push the towing vehicle sideways (tractor jackknife).
The rig will stay in a straight line but slide sideways.
The trailer will the trailer has overturn.
8. Truck tractors with air brakes built after March 1, 1997, are required to be equipped with:
anti-lock brakes.
a rear backup camera.
hydraulic brakes.
9. If an item placed on a flatbed trailer is 7 feet long, it should have __ tie-downs.
10. When possible, you should park:
on the roadway.
on the shoulder.
so you will be able to pull forward when you leave.
so you will have to back up when you leave.
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OR CDL Doubles Triples Test

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