To review the first iteration in its entirety, let’s look at a real-world example. Ian McHarg's study of the Richmond Parkway in New York illustrates the first iteration models well in the context of transportation planning. Be sure to read Design with Nature. Ian McHarg. Chapter 4: A Step Forward for the full story.

A Real-World Example: Richmond Parkway

The Richmond Parkway is a more complex study and more closely represents the type of situation that one would use for a geodesign process. In this second example of a problem, we will again look at each of the six models; however, both the questions and the answers are more richly detailed. Working out these questions in order to get good information to inform the study is what makes this first iteration of the framework essential.

Representation Models

Representation Models: ask how should the area be described in content, time, and space; or what are the limits or boundaries of the study area? McHarg defines the study as a composition of social and economic values expressed through geographic characteristics in an approximately 30 square mile region. The boundary for the study area appears to be defined by the geographic area that could encompass the proposed parkway alignment and the Greenbelt.

Process Models

Process Models: ask how does the study area operate or what actions or activities happen in the study area. Many physiologic and human processes are defined in the study area. The broad processes for the study area are: geologic (soil, slope, bedrock, erosion), economic (land value, residential value), and social (historic, scenic, recreation, water, forest, wildlife, institutional).

Evaluation Models

Evaluation Models: ask how well is the current study area performing? McHarg does not expressly define his parameters for determining how well the study area is performing, but we can draw two assumptions from the problem. First, the need to propose a new parkway alignment suggests that transportation in the area could be improved. Second, the Greenway is performing well as a socially rich feature for the area. From these assumptions we can conclude that the parkway alignment needs to be efficient, from both transportation and cost perspectives, and that the Greenway's social contributions should be protected.

Change Models and Impact Models

Change Models and Impact Models: look forward in time and asks what known changes may occur in the study area. McHarg does not define any known changes to the study area. However, we can assume that some growth can be expected in the area if a new parkway is being proposed. With new growth, we can reasonably predict that traffic to and from the study area will increase to some degree.

Decision Models

Decision Models McHarg address the stakeholders early in the study, and often in practice a team will be in contact with a small stakeholder group who are clear about their expectations and values. McHarg identifies the initial values of the stakeholders to be cost-effective planning and economic efficiency. He further identifies a hidden social value within a separate group of stakeholders – the study area's population. The balance between these two sets of values help to define McHarg's methodology for proposing a new parkway alignment.