Horizontal Geometry

Horizontal geometry for alignments can be described using:

• Lines

• Curves

• Spirals

  • Clothoid

  • Bloss

  • Cubic Spiral

  • Cubic parabola

For single carriageway/track alignments, the horizontal alignment must occur within the pavement/ballast extents.

For dual carriageway/track, the horizontal alignment must occur within the center median. For dual carriageway/track alignments, the alignments can’t have variable relationships (vertical or horizontal separation). If alignments do have variable relationships they will have to be modeled by importing the carriageway/tracks independently.

Horizontal geometry is expected to not have any alignment breaks or gaps. The alignment is expected to continue through bridges and tunnels and station equations are not supported.

Next topic: Vertical Geometry