Land resource units that are defined by their physical properties can be characterized quantitatively using engineering test data. Information about substrate properties in quantitative terms confirms and augments qualitative statements about the physical characteristics of land resource units. This information should allow a more accurate definition of environmental limits and may reduce the need for preliminary engineering investigations commonly undertaken to assess project feasibility and to estimate costs.

Quantitative information should also aid planners in charting utilization of land consistent with its natural suitability or in identifying the approximate level of engineering necessary to render a particular site suitable, thereby maximizing resource use.