Surfacing a survey also creates a design

Surfacing collected survey points creates a terrain model of the field’s original elevation. T3RRA also automatically creates a design surface that is an exact duplicate of this original elevation surface.

This duplicate provides a base layer to work from: T3RRA allows design surfaces in separate regions of a field, as well as design surfaces based on existing design surfaces.

Because a design surface is created automatically, you can go straight to implementation after surfacing even if you have not specifically created a design. Surfacing is normally automatic, so you can usually go directly from collecting to implementing. A design surface does exist, but it duplicates the original elevation surface, so the cut/fill map contains 0 values across the whole field.