What does the term "PI" represent in highway design?

In highway design, the term "PI" stands for Point of Intersection. This is a critical element in the design of road alignments, as it refers to the point where two road curves or centerlines intersect. The Point of Intersection is pivotal for establishing the geometry of the road, including aspects like curvature, superelevation, and sight distance, which are essential for ensuring safety and efficient traffic flow.

Understanding the Point of Intersection helps engineers determine how vehicles will navigate through curves and ensure that alignment changes are smooth. This knowledge is indispensable for creating effective and safe highway designs. The other terms, while they may pertain to different contexts in engineering or design, do not apply to the specific geometric considerations of highway design in the same way as Point of Intersection does.