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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. Placards are:
devices placed below a vehicle to improve traction.
a type of safety equipment.
signs put inside a vehicle used to warn others of hazardous materials.
signs placed on a vehicle to identify the hazard class of the cargo.
2. When backing a trailer, you should turn the steering wheel to the right to make the trailer go left (or vice versa). Once the trailer starts to turn, you should:
keep backing up.
turn the wheel more  in the direction you want to go.
turn the wheel the other way to follow the trailer.
None of the above.
3. Another name for front-end header boards is:
head belt.
headache racks.
cargo stopper.
containerized racks.
4. The tire load for each tire is stated:
on the inside of the tire.
on the side of the tire.
on the tread of the tire.
on the vehicle's operator manual.
5. Most heavy-duty vehicles use:
solid brakes.
pressure brakes.
air brakes.
hydraulic brakes.
6. _________ rigs are much more likely to roll over in an accident than _________ rigs.
Fully loaded ; overloaded
Empty ; fully loaded
Empty ; overloaded
Fully loaded ; empty
7. It is safer to drive over (rather than to avoid) which of the following?
Plastic containers
Cardboard boxes
Paper and cloth sacks
None of the above.
8. For safety during a trip, you should:
watch gauges for signs of trouble.
check critical items when you stop.
use your senses to check for problems.
All of the above.
9. When driving in very hot weather, you may have to:
watch out for black ice.
increase your speed until the tires cool off.
decrease your following distance.
reduce your speed to prevent overheating.
10. You hear a loud "bang" which sounds like a tire blowout. You should:
inspect your tires with your mirrors.
check the tires at the next stop.
keep driving as normal.
assume you have a tire failure.
 
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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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