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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. When coupling, you should:
make sure the trailer wheels are not chocked.
make sure the sliding fifth-wheel is locked.
make sure the trailer kingpin is bent.
be aware that wrong coupling and uncoupling can be very dangerous.
2. If an aggressive driver is involved in an accident down the road, you should:
try to get their vehicle to the side of the road.
make eye contact with the driver.
confront the aggressive driver.
stop a safe distance from the accident scene, wait for the police and report the behavior you witnessed.
3. If you are being tailgated, you should:
open up room in front of you.
increase your speed very gradually.
make quick changes.
turn on your taillights.
4. Before driving a vehicle with a dual air system, allow time for the air compressor to build up a minimum of ____ pressure in both the primary and secondary systems.
75 psi
25 psi
50 psi
100 psi
5. Large vehicles take longer to stop when they are:
carrying hazardous materials.
heavily loaded but not fully loaded.
fully loaded.
6. When driving double and triple trailers, drivers should:
steer gently and go slowly around corners.
allow more following distance.
look far ahead.
All of the above.
7. If an aggressive driver confronts you, you should NOT:
try to get out of their way.
try to let them pass.
ignore gestures.
make eye contact.
8. In newer vehicles with air brakes, you put on the parking brake:
using a diamond-shaped, yellow, push-pull control knob.
placing the transmission in Park.
moving the orange push-pull lever to the right.
using a P-shaped, yellow control knob.
9. Warnings on low bridges or underpasses:
are often posted, but sometimes they are not.
are always posted.
must be posted.
None of the above.
10. You are driving a vehicle with air brakes when the low air pressure warning light and buzzer come on. You should:
activate your hazard lights and drive to the nearest place where you can stop.
apply the brakes as hard as you can.
slow down and test your brakes.
pull off the road and stop immediately.
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MD CDL Doubles Triples Test

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