Graphical Solution for Vertical Curve Computation

Traditionally, highway vertical curve data have been calculated and tabulated for construction staking. The design drawing showed the parabola drawn using the calculated station-offset information. With the procedure described herein, a draftsperson can draw the parabola, given the station-elevation data on the beginning of vertical curve, the point of vertical intersection, and the end of vertical curve, using any drafting software. The construction staking data can then be obtained directly from the drawing by means of an appropriate command to get the information. There is no need to compute the grade elevation for staking purposes. While the graphical methods are not new, the use of computer-aided drafting (CAD) facilitates obtaining precise solutions from the CAD-computed database, which was not possible with the paper drawings of the past.