A slope analysis is often the first physical planning study undertaken when urban development on a vacant site, or the expansion of an urban area, is contemplated. This slope analysis is often accepted as the basic study which, to a great degree, determines the uses of land. The determination of economically feasible land uses, by the nature of the landform, is then modified by the application of social, economic, and other goals and constraints; however, the form of the land is usually the first consideration made in an urban planning site analysis. The slope analysis can provide guides to the land uses and patterns that could exist in the area if economy in physical construction, based on ground slope qualities, were the only influence on urban form and structure. A way of visualizing slope is to think of the grades of various types of streets.