Getting Started - Autodesk Roadway Design for Infraworks 360 Essentials - page 5

Curves Curves are the curved portions of
a baseline that have a constant radius.
Spiral A spiral is a curved portion of a
baseline that changes in radius from one
end to the other. Most curves have a
spiral placed at the beginning and end.
Point of intersection (PI) PI is the
place where two tangents intersect or
would intersect if they were extended.
Point of curvature (PC) PC is the place
where the curve begins.
Point of tangency (PT) PT is the place
where the curve ends.
Point of reverse curvature (PRC)
PRC is the place where one curve meets
another and the curve directions are
different.
Point of compound curvature (PCC)
PCC is the place where one curve meets
another and the curve directions are the
same.
Rules-Based Design
AASHTO stands for the American
Association of State Highway and
Transportation Officials.