El Dorado County's new road had to stay within the limits of the land that was purchased for the project, shown as the gray area. The blue line represents the proposed roadway alignment. The dashed green lines show the minimum placement distance for utility poles. Images: Autodesk
Using the road centerline alignment along with profile and cross-section information, transportation engineers could see how much earthwork (shown in yellow in plan view) the new road would require. Note that the extents exceed the gray right-of-way area near the curve.
Whenever information about one element — alignment, profile, or cross-section —is tweaked, the modeling software instantaneously presents a visual of the impact on all the other elements. In this way, engineers worked several iterations by adjusting the alignment to make sure that both the minimum distance for pole placement requirement was met and grading stayed within the right of way.
Because analysis and documentation are dynamic, engineers received immediate feedback on design feasibility. When placing utility poles, they could see the placement in three dimensions and check to ensure slopes were within tolerance. The colored portion shows slope analysis; red areas are the steepest and green the least steep. On the right are annotated cross-section and plan views.