Do highway improvements at or near a place stimulate land development at that place? Or does land development promote highway development to serve that place? What is the relationship between land and transportation development, and is that relationship constant or does it change over the years?

These are questions Professor John Adams, Department of Geography, and research team members Laura Hansen and Barbara VanDrasek are investigating as part of the Transportation and Regional Growth Study. Adams discussed the team’s findings thus far in a presentation titled "Measuring the Connections: Highway Improvements and Land Development Patterns in the Greater Twin Cities Area, 1970-1995" at the Study’s first fall research workshop on September 23.

About 50 faculty, students, and practitioners attended Adams’ presentation on the relationships between highway transportation and patterns of land development in suburban and exurban areas and the way in which development seems to follow as well as lead transportation improvements. Early findings of the research suggest that the impact of major highway improvements on land development patterns took one form in the 1960s, another in the 1970s, and still other forms in recent years.

The relationship between land development and transportation is not a new topic, Adams said. Such relationships began in this country with the trails and waterways used for movement by Native Americans, explorers, and fur traders. Those routes were gradually adopted and expanded upon by railroads, which reinforced advantageous geographical positions that both led and followed agricultural settlement. Throughout the following decades, state, federal, and then interstate highways continued the expansion, promoting farm and urban development, linking prominent metro areas, and eventually opening up outlying areas for development.

In their analysis, Adams' research team considered the 631 different minor civil divisions (MCDs) -- local units of government of cities, towns, and townships -- in the 24-county Twin Cities study area. Each MCD was assigned a transportation score ranging from 0-12, according to the presence of one or more arterial highways within or adjacent to it. Land development was classified by four types: residential, commercial, industrial, and office, and measured based on building-permit data reporting the number of permits issued or the value of new construction during the study period of 1970-97. The residential and industrial development data were standardized to account for the availability of vacant land, while the commercial development data were standardized to account for existing population density.

From its statistical analysis, the team found that transportation improvements are just one element that influences development; other variables, some still unknown, contribute to location decisions as well. The research shows that relationships between highway improvements and land development patterns vary through time and among different types of development. Also, although transportation and the four types of land development were closely linked in the 1970s and especially in the 1980s, in the 1990s that relationship drops off and loses its significance.

"One of the most interesting things about the report is what happens in the 90s," Adams said. According to Adams, something else is going in the 90s, although it’s not yet clear what that is. The 90s are characterized by a "movement field," a contrast to the initial radial development pattern of the metropolitan area. As circumferentials and branches were added through time, the relationships between transportation improvements and development patterns became much less predictable.

Members of the audience asked how transportation accessibility issues (e.g., congestion on major highways) influence development. Adams said that although the current phase of their research does not consider those factors, he agrees that the two may be linked in this era of "ubiquitous travel."

In terms of development and transportation planning, the study’s findings can be useful when considering, "What kind of metro area are we becoming, and what kind of area do we want to become?" Adams said.

The next task of the project will be to fit together all the pieces the team has collected, using case studies to illustrate how the elements work together.

For more information on this project, contact Gina Baas of CTS at 612-626-7331 or baasx001@cts.umn.edu.