Create Horizontal Alignment: PI Based

Create a new 2D DGN file and open the file.

The "Place PI Alignment" tool is available as shown below:

Screen shot

This tool was originally written for Minnesota DOT.

Potential uses are:

  • A method for entering existing (known) horizontal geometry for creating a chain.
  • A nice replacement for the old COGO method for creating an open alignment.
  • Modifying a chain dynamically using the following built in options:
    • Lock/Unlock PI coordinates
    • Insert/Delete/Move PI point
    • Lock/Unlock tangent direction
    • Move tangent
    • Dynamically modify curve radii

The tool cannot handle SCSCS curves.

I intend to explore this tool further and document some instructions for it later.

For now, please use the Horizontal Alignment Generator.