TruckingTruth logo

Combination Vehicles Free CDL Practice Tests
Page 1

Prepare For The Combination Vehicles Portion Of Your CDL Written Exams

Combination Vehicles Questions

Click On The Picture To Begin

Good Luck!

The likelihood of a fully loaded rig turning over compared to an empty trailer is:
  • 10 times
  • The same
  • Unknown
  • 5 times
Click here to look up the answer

From The CDL Manual

Rollover Risks—

More than half of truck driver deaths in accidents are the result of truck rollovers. When more cargo is piled up in a truck, the “center of gravity” moves higher up from the road. The truck becomes easier to turn over. Fully loaded rigs are 10 times more likely to roll over in a crash than empty rigs.

Next
Over 50% of truck driver accident deaths are caused by:
  • Explosions
  • Rollovers
  • Bridge collapse
  • Brake failure
Click here to look up the answer

From The CDL Manual

Rollover Risks—

More than half of truck driver deaths in accidents are the result of truck rollovers. When more cargo is piled up in a truck, the “center of gravity” moves higher up from the road. The truck becomes easier to turn over. Fully loaded rigs are 10 times more likely to roll over in a crash than empty rigs.

Prev
Next
One good way to prevent rollover is:
  • Pile cargo high in the middle of the trailer
  • Keep cargo on the side you are most likely to turn towards
  • Keep cargo as low as possible
  • Stack all cargo towards the rear of the trailer
Click here to look up the answer

From The CDL Manual

Two things will help prevent rollover: keeping the cargo as close to the ground as possible, and going slowly while turning. Keeping cargo low is even more important in combination vehicles than in straight trucks.

Prev
Next
To help prevent rollover, keep the center of gravity of the load as low as possible, and:
  • Coast to a stop
  • Pump the brakes when stopping
  • Turn in the direction you want your cargo to shift
  • Take turns slowly
Click here to look up the answer

From The CDL Manual

Two things will help prevent rollover: keeping the cargo as close to the ground as possible, and going slowly while turning. Keeping cargo low is even more important in combination vehicles than in straight trucks.

Prev
Next
Rocky mountain doubles have a rearward amplification of about:
  • 2.5
  • 3
  • 2
  • 1.5
Click here to look up the answer

From The CDL Manual

See Figure 6-1 Influence of Combination Type on Rearward Amplification on page 70 of the CDL manual
Prev
Next
Rearward amplification is a major cause of:
  • Jack-knifing
  • Trailer rollover accidents
  • Massive air loss
  • Brake failure
Click here to look up the answer

From The CDL Manual

Rearward Amplification —

Trucks with trailers have a dangerous “crack-the-whip” effect. When you make a quick lane change, the crack-the-whip effect can turn the trailer over. There are many accidents where only the trailer has overturned.

Prev
Next
Triples combinations have a rearward amplification of:
  • 3.5
  • 2.5
  • 1.0
  • 2
Click here to look up the answer

From The CDL Manual

“Rearward amplification” causes the crack-the-whip effect. Figure 6-1 below shows eight types of combination vehicles and the rearward amplification each has in a quick lane change. Rigs with the least crack-the-whip effect are shown at the top, and those with the most at the bottom. Rearward amplification of 2.0 on the chart means that the rear trailer is twice as likely to turn over as the tractor. You can see that triples have a rearward amplification of 3.5. This means you can roll the last trailer of triples 3.5 times as easily as a 5-axle tractor-semi.
Prev
Next
The "rearward amplification" value means:
  • How likely it is that the brakes will lock up when stopping
  • How loud it is inside the trailer
  • The likelihood that you blow the rear speakers in the cab
  • How easily you can roll the last trailer, i.e. 3.0 = 3 times as likely
Click here to look up the answer

From The CDL Manual

Rearward amplification of 2.0 on the chart means that the rear trailer is twice as likely to turn over as the tractor. You can see that triples have a rearward amplification of 3.5. This means you can roll the last trailer of triples 3.5 times as easily as a 5-axle tractor-semi.

Prev
Next
When traveling under 40 mph, how much distance should you leave, at minimum, from the car in front of you?
  • 1 second for every 10 feet
  • 10 seconds for every 10 feet
  • 40 feet
  • 1 second for every car length
Click here to look up the answer

From The CDL Manual

Steer Gently

Steer gently and smoothly when pulling trailers. If you make a sudden movement with your steering wheel, you could tip over. Follow far enough behind other vehicles (at least 1 second for each 10 feet of your vehicle length, plus another second if going over 40 mph). Look far enough down the road to avoid being surprised and having to make a sudden lane change. At night, drive slow enough to see obstacles with your headlights before it is too late to change lanes or stop gently. Slow down to a safe speed before going into a turn.

Prev
Next
When pulling trailers:
  • Look far enough down the road to avoid being surprised and having to make a sudden lane change.
  • Steer gently and smoothly
  • These are all good rules to follow when driving combination vehicles
  • Slow down to a safe speed before going into a turn
Click here to look up the answer

From The CDL Manual

Steer Gently

Steer gently and smoothly when pulling trailers. If you make a sudden movement with your steering wheel, you could tip over. Follow far enough behind other vehicles (at least 1 second for each 10 feet of your vehicle length, plus another second if going over 40 mph). Look far enough down the road to avoid being surprised and having to make a sudden lane change. At night, drive slow enough to see obstacles with your headlights before it is too late to change lanes or stop gently. Slow down to a safe speed before going into a turn.

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

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!
  • 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