A tractor without a semi-trailer

A tractor with two semi-trailers

A tractor that goes faster than the speed limit

A tractor that goes slower than the speed limit

Are more likely to roll over than empty rigs.

Are less likely to roll over than empty rigs.

Are just as likely to roll over as empty rigs.

South Dakota CDL Combination 1 - DMV Written Test Questions with Answers

Q.1

Combination vehicles are usually:

Easier to drive than single commercial vehicles.
Lighter than single commercial vehicles.
More difficult to drive than single commercial vehicles.

Q.2

What is a bobtail?

A tractor without a semi-trailer
A tractor with two semi-trailers
A tractor that goes faster than the speed limit
A tractor that goes slower than the speed limit

Q.3

If unsure if a trailer has an Anti-Lock Braking System (ABS), you can:

Look under the trailer for wheel speed sensors coming from the back of the brakes.
Remove a tire and look for the ABS sensor on the axle.
Assume it does have ABS.

Q.4

Which of the following types of vehicles is most prone to the “crack-the-whip" effect?

An automobile
A three-axle tractor
A bobtail tractor
A triple combination

Q.5

Fully-loaded rigs:

Are less likely to roll over than empty rigs.
Are more likely to roll over than empty rigs.
Are just as likely to roll over as empty rigs.
Should not be driven.

Q.6

Using the trailer hand valve while driving:

Will help you turn safely.
Will stop your trailer safely.
Can cause a skid.
Is impossible.

Q.7

When entering or crossing traffic while driving a combination vehicle, it is especially important that you:

Sound your horn.
Make sure there is a large enough gap for your vehicle.
Expect other drivers to make room for your vehicle.
Let other drivers wave you into their lane.

Q.8

If color-coded, which color is used to identify service lines?

White
Yellow
Blue

Q.9

When driving with trailers, you should:

Make quick, sudden changes.
Avoid making sudden moves.
Accelerate by pushing the accelerator to the floor.

Q.10

Which type of vehicle is most prone to the “crack-the-whip” effect?

A five-axle tractor semi-trailer
A three-axle tractor semi-trailer
A bobtail tractor
A triple trailer

Q.11

Driving a combination vehicle ____ than driving a single vehicle.

Is easier
Requires more driving skill
Is better for training
Is safer in inclement weather

Q.12

To help prevent a rollover, cargo should be:

Placed as high as possible inside the trailer.
Placed as low as possible inside the trailer.
Placed on the passenger side of the trailer.
Placed on the driver’s side of the trailer.

Q.13

All trailers made after ____ must be equipped with Anti-Lock Braking Systems (ABS).

1943
1998
2009

Q.14

When a combination vehicle goes around a corner:

The vehicle must use at least two lanes.
The front and rear wheels will move in different paths.
It is best to allow the rear wheels to drive over the curb.

Q.15

Before a drive, ensure that air flows to all trailers by:

Opening the rear shut-off valves and listening for escaping air.
Closing the rear shut-off valves and listening for escaping air.
Disconnecting air supply lines and listening for escaping air.
Rolling each trailer down a hill and testing the brakes.

Q.16

Look for matching colors when coupling glad hands. Service lines are often:

Green.
Orange.
Red.
Blue.

Q.17

A loss of air pressure in the emergency line will cause:

The suspension springs to extend.
The tractor protection valve to open.
The rear trailer to detach from the combination.
The emergency brakes to activate.

Q.18

When braking with ABS, you should:

Push the brake pedal harder than usual.
Push the brake pedal as you normally would.
Push the brake pedal more lightly than usual.

Q.19

How much space should be between the upper and lower fifth wheel?

About five inches of space
A maximum of two inches of space
No space

Q.20

If the trailer begins to skid, it is best to:

Release the brakes.
Accelerate.
Quickly turn the steering wheel one way, then the other.
Brake.