2.0

Table Of Contents

Chapter 3 Working with Profiles and Vertical Alignments

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NOTE

If the Define Ditch/Transition command displays the message No vertical

exists, you cannot reference the finished and existing ground information

to the same station or location. Use the Set Current Profile command to

verify the location of the existing ground data then define the vertical

alignment.

The following illustration shows the points required to define the finished

ground alignment:

Defining finished ground

Defining a Ditch or Transition by Offsetting an

Existing Vertical Alignment

As an alternative to drawing ditch or transition alignments, you can use the

finished ground centerline (or any other vertical alignment) definition to create

ditches and transitions by calculating a change in elevation based on offset and

grade. The Define by Offset/Grade command uses a grade and offset value to

create a new vertical transition alignment with elevations calculated in relation

to an existing vertical alignment.

You can choose to create the new vertical alignment at a uniform offset from

the existing alignment, or you can base the offset distance on a horizontal

alignment that may have a non-uniform offset distance (such as for a passing

lane):

When you base the offset distance on a uniform offset, you must specify the

uniform offset distance you want to use.

When you base the offset distance on an alignment, you are not prompted

for an offset distance. Instead, you must specify which horizontal alignment

to use to determine the offset distance.

Creating a Vertical Alignment at a Uniform

Offset from the Reference Alignment

Use the Uniform option of the Define by Offset/Grade command to offset a

vertical alignment at a constant offset distance. The alignment that you offset