Floating zones are zoning districts and provisions for which locations are not identified until enacted for a specific project. Such zones are used to anticipate certain uses, such as regional shopping centers, for which locations will not be designated on the zoning map until developers apply for zoning. They usually require special review procedures. Montgomery County (MD) has pursued aggressively the development of higher densities around Metro-rail stations. Of particular value in this effort was the creation of floating zones that permit higher densities in some business areas subject to design review and contributions of amenities. The zoning provisions have been applied particularly in rail/bus station areas to encourage transit-friendly development and a high order of design and appearance. Case/Example: Bethesda transit-station area in Montgomery County (MD). Source/Reference: Porter, 1997, pp. 26 and pp. 38.