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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 Delaware doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The DE CDL doubles triples test covers the following sections of the Delaware CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this DE CDL practice test now to prepare for the actual test!
1. ABS helps you:
decrease your overall stopping distance.
keep the wheels from locking up.
decrease your average speed.
lock your wheels.
2. Enough tread is especially important in winter conditions. You need at least ________ tread depth on steering axle tires.
4/32 inch
6/24 inch
8/32 inch
2/8 inch
3. The ABS malfunction lamp on the instrument panel is:
4. If a load is placed on one side of the trailer:
making turns may be easier.
the steering axle weight will be too light to steer safely.
a rollover is more likely.
your brakes won't work.
5. Watch out for black ice:
right after it starts to rain.
any time the temperature is below freezing and the road looks wet.
when the temperature is above freezing and the road is dry.
when it is snowing.
6. To prevent a rollover, the driver should:
drive on the shoulder if possible.
drive slowly around corners, on ramps, and off ramps.
pay extra attention to the coolant level.
make quick lane changes if possible.
7. If you unlock the pintle hook with the dolly still under the rear trailer:
the brakes could be damaged by the combined forces of the springs and the air pressure.
the dolly tow bar may fly up.
steam and boiling water can spray under pressure.
your vehicle might roll away.
8. Texting is:
safer thanĀ  engaging in conversation with a passenger.
about as safe as adjusting the radio.
safer than talking on a cell phone.
the most dangerous distraction.
9. To warn drivers behind you when you see you'll need to slow down, you should:
flash the brake lights.
sound your horn.
use your headlights.
turn off your lights.
10. If you must stop on a one-way or divided highway, place your warning devices:
10 feet, 100 feet, and 200 feet toward the approaching traffic.
50 feet, 100 feet, and 150 feet toward the approaching traffic.
100 feet, 200 feet, and 300 feet toward the approaching traffic.
10 feet, 50 feet, and 150 feet toward the approaching traffic.
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DE CDL Doubles Triples Test

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