Historically, the Master Plan contemplated a fixed vision of the City (20) or (30) years in the future. Today, this is not usually appropriate. Comprehensive or Master Plans are, by their nature, flexible and subject to periodic change. A well conceived plan is an expression of local policy, articulated in the form of a map or maps and text which provides a "soft" blueprint of the future of the community. The use of the Comprehensive Plan map is important because, by its spatial nature, it organizes decision making on land use decisions, and can give a more meaningful perspective to capital improvements programming.
A land use plan sets aside locations for land uses and allocates a certain amount of space for each land use, while connecting land uses with the transportation network. Setting aside locations involves applying planning principles based on accessibility needs, the relative need to be located close to similar uses, the site needs, and the external effects of each land use. These principles are consistent and cut across different communities. However, the amount of space allocated for each category must be particular to each planning area. The population, market, and economic studies that go into a plan are primarily aimed at helping to determine how much space should be provided for each category of land use. The balance between location and space is a delicate one. There are areas of conflict or transition where locational characteristics alone cannot determine the most appropriate land use. One community may have more demand for industrial land, another for office, another for multiple family residential use. A parcel with the same locational characteristics thus could very well be utilized for three different uses in three different communities based on space demand or the vision of the community.
Since developers and builders are the ones who build cities, and since their projects must be responsive to a changing and unpredictable market, comprehensive plans likewise must change from time to time if they are to be effective and have credibility. However, because the Master Plan represents continuity between the past, present, and future, reflecting underlying change, while desirable, must only be accomplished after thorough scrutiny. Otherwise, too much sensitivity to change would render the plan not a plan, but simply a reflection of today’s development fashion and point in the economic cycle. Thus, the Master or Comprehensive Plan must strike a balance which acknowledges and promotes flexibility, yet retains its long range sense of direction and purpose.