When user input points on curve, program will use least square method to fit a second order polynomial curve. Points on curve can be classified into point on straight slope (ID=1) and point on curve (ID=2). The first point on curve will assigned as PVC and the last point on curve will be assigned as PVT. If only a curve is specified, the first point should have ID of 1.
PI points should be arranged from lower station to higher station. Each PI point requires station and elevation data. The K factor of vertical curve is the length of the vertical curve divided by the algebraic difference of the slope of the tangents on each side of the curve divided by 100.
K = L/(100*A)where: