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| Figure 9.8 A cross-section view of a road that shows the daylighting of a 3:1 slope on either side |
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Understanding Surface Targets
on July 19, 2018
Surface targets are used in a number of cases where the corridor needs to interact with a surface, such as when a slope is projected from a design elevation to the point where it intercepts an existing ground surface. This is referred to as daylighting. For example, in a section of road design that is above existing ground, daylighting would be used to create the embankment from the elevation of the road to the original ground elevation (see Figure 9.8).
Although daylighting is the most common example of surface targeting, there are other examples such as establishing the cross slope of an existing road, setting the top elevation of a retaining wall, setting the depth of a pipe, and many others.