What equation is not included in vertical curve calculations?

• A. PVCsta=PVIsta+L/2
• B. PVCsta=PVIsta-L/2
• C. PVIsta=Pvcsta-L/2
• D. PVIsta=Pvcsta+L/2

Answer: (B)

The question focuses on the relationships between critical points in vertical curves, specifically the points of vertical intersection (PVI) and the points of vertical curvature (PVC). In vertical curve calculations, the main goal is to establish the geometric and algebraic relationships to determine the vertical alignment of a roadway.

The correct answer highlights an equation that does not represent a standard calculation for vertical curves. Specifically, the equation that involves subtracting half of the length of the curve (L/2) from the station of the PVI to find the station of the PVC is inconsistent with the typical geometry of a vertical curve.

In vertical curve calculations, the PVC is located before the PVI when moving in the direction of increasing stationing. This means that the station of the PVC should be found by adding half the length of the curve (L/2) to the station of the PVI when working from the PVI towards the PVC. Therefore, any correct equation will add L/2 when moving from the PVI to the PVC, not the other way around.

Other options illustrate proper relationships. One equation correctly expresses the relationship by incorporating addition to move from the PVI to PVC, while the other options effectively maintain the alignment of points on the curve through correct