TruckingTruth logo

Doubles And Triples Free CDL Practice Tests
Page 1

Prepare For The Doubles And Triples Portion Of Your CDL Written Exams

Doubles And Triples Questions

Click On The Picture To Begin

Good Luck!

In terms of stability, doubles and triples are:
  • Just as stable as regular commercial vehicles
  • More stable than regular commercial vehicles
  • Less stable than regular commercial vehicles
  • Too dangerous to drive during the day
Click here to look up the answer

From The CDL Manual

7.1 – Pulling Double/Triple Trailers

Take special care when pulling two and three trailers. There are more things that can go wrong, and doubles/triples are less stable than other commercial vehicles. Some areas of concern are discussed below.

Next
A safe speed on a curve for a smaller commercial vehicle:
  • Is 45 mph
  • May not be safe for doubles or triples
  • Is too slow for doubles or triples
  • Will definitely be safe for doubles or triples
Click here to look up the answer

From The CDL Manual

Prevent Trailers From Rolling Over —

To prevent trailers from rolling over, you must steer gently and go slowly around corners, on ramps, off ramps and curves. A safe speed on a curve for a straight truck or a single trailer combination vehicle may be too fast for a set of doubles or triples.

Prev
Next
The increased likelihood of doubles and triples turning over is called:
  • The spit-and-shine effect
  • The shoot-the-moon effect
  • The crack-the-whip effect
  • The roll-the-bones effect
Click here to look up the answer

From The CDL Manual

Crack-the-Whip Effect —

Doubles and triples are more likely to turn over than other combination vehicles because of the “crack-the-whip” effect. You must steer gently when pulling trailers. The last trailer in a combination is most likely to turn over. If you do not understand the crack-the-whip effect, study Section 6.1 and review Figure 6-1 on page 70.

Prev
Next
The part of the combination vehicle most likely to turn over is the:
  • Entire vehicle
  • First trailer
  • Tractor
  • Last trailer
Click here to look up the answer

From The CDL Manual

Crack-the-Whip Effect —

Doubles and triples are more likely to turn over than other combination vehicles because of the “crack-the-whip” effect. You must steer gently when pulling trailers. The last trailer in a combination is most likely to turn over. If you do not understand the crack-the-whip effect, study Section 6.1 and review Figure 6-1 on page 70.

Prev
Next
Drivers of doubles and triples must take into greater account:
  • These are all things that require increased awareness when driving doubles and triples
  • Managing a larger space
  • More critical parts requiring inspection
  • Increased stopping distance and looking farther ahead
Click here to look up the answer

From The CDL Manual

Inspect Completely —

There are more critical parts to check when you have two or three trailers. Check all of them by following the procedures described later in this section.

Look Far Ahead —

Doubles and triples must be driven very smoothly to avoid rollover or jackknife. Therefore, look far ahead so you can slow down or change lanes gradually when necessary.

Manage Space —

Doubles and triples take up more space than other commercial vehicles. They are not only longer, but also need more space because they cannot be turned or stopped suddenly. Allow more following distance. Make sure you have large enough gaps before entering or crossing traffic. Be sure you are clear at the sides before changing lanes.

Prev
Next
When driving doubles or triples in adverse or slippery weather conditions, all of the following are true except:
  • Loss of traction is a bigger concern
  • There is greater chance of a skid
  • They are easier to control
  • You must be especially careful
Click here to look up the answer

From The CDL Manual

Adverse Conditions —

Be more careful in adverse conditions. In bad weather, slippery conditions and mountain driving, you must be especially careful if you drive double and triple bottoms. You will have greater length and more dead axles to pull with your drive axles than other drivers. There is more chance for skids and loss of traction.

Prev
Next
If the rear trailer does not have spring brakes, disconnecting the emergency line after charging will:
  • Release the emergency brakes
  • Ruin the trailer brake system
  • Guarantee that the trailer will not move
  • Set the emergency brakes
Click here to look up the answer

From The CDL Manual

Secure second (rear) trailer:

If the second trailer does not have spring brakes, drive the tractor close to the trailer, connect the emergency line, charge the trailer air tank, and disconnect the emergency line. This will set the trailer emergency brakes (if the slack adjusters are correctly adjusted). Chock the wheels if you have any doubt about the brakes.

Prev
Next
When driving doubles or triples, for safer handling which trailer should be at the rear?
  • The lighter trailer
  • The shorter trailer
  • It doesn't matter
  • The heavier trailer
Click here to look up the answer

From The CDL Manual

Caution:

For the safest handling on the road, the more heavily loaded semi-trailer should be in first position behind the tractor. The lighter trailer should be in the rear.

Prev
Next
After coupling the converter dolly to the first trailer, the pintle hook should be:
  • Open
  • Ignored
  • Removed
  • Locked
Click here to look up the answer

From The CDL Manual

Move dolly to rear of first semi-trailer and couple it to the trailer.

Lock pintle hook.

Prev
Next
A converter dolly is used:
  • Only in emergency
  • To convert AC electricity to DC
  • To couple a second (or third) trailer behind another trailer
  • Only in Canada
Click here to look up the answer

From The CDL Manual

Couple tractor and first semitrailer as described earlier:

A converter gear or dolly is a coupling device of one or two axles and a fifth wheel by which a semitrailer can be coupled to the rear of a tractor-trailer combination forming a double bottom rig.

Prev
Finish
Please select an option
[3,2,3,4,1,3,4,1,4,3]
10

Select A New Page Of Doubles And Triples Practice Questions

Join Us!

We have an awesome set of tools that will help you understand the trucking industry and prepare for a great start to your trucking career. Not only that, but everything we offer here at TruckingTruth is 100% free - no strings attached! Sign up now and get instant access to our member's section:
High Road Training Program Logo
  • The High Road Training Program
  • The High Road Article Series
  • The Friendliest Trucker's Forum Ever!
  • Private messaging for more personal questions
  • Email Updates When New Articles Are Posted

About Us

TruckingTruth was founded by Brett Aquila (that's me!), a 15 year truck driving veteran, in January 2007. After 15 years on the road I wanted to help people understand the trucking industry and everything that came with the career and lifestyle of an over the road trucker. We'll help you make the right choices and prepare for a great start to your trucking career.

Read More

Becoming A Truck Driver

Becoming A Truck Driver is a dream we've all pondered at some point in our lives. We've all wondered if the adventure and challenges of life on the open road would suit us better than the ordinary day to day lives we've always known. At TruckingTruth we'll help you decide if trucking is right for you and help you get your career off to a great start.

Learn More