Sunday, May 25, 2008

Visualizing Postwar Sprawl

A mapping exercise to investigate how Dayton grew after WWII, drawn atop a base map.

To 1941-1950

First, subdivided areas as of 1950. This is mostly prewar Dayton + a few wartime developments and very early postwar plats. One can see how the city was starting to extend out along interurban lines, plus some early auto-oriented plats. Most of this was pre-Depression development, and there apparently was a lot of infill and re-platting of dead subdivisions going on during the immediate postwar era.

To 1970-1973

Orange color maps out suburbanization due to the postwar boom of the 1950s and 1960s mostly. The early 70s is the cutoff point as Montgomery County population stops growing more or less after 1970, and the manufacturing economy here starts to stall starting with the NCR shutdown in the early 1970s. This is also pre-I-675 growth. Whats not shown is the ribbon development that is found the country roads.

To 2000-2008

Yellow shows suburbanization since the early 1970s. Most of this is really 1980s on. Here one sees the real boom across the county lines in Greene and especially northern Warren County. Unfortunately the growth east is truncated due to the map not showing more of Greene County.


Removing the base map and drawing in the expressway system one gets a better picture on how Dayton grew beyond the old city, or prewar city (which includes Oakwood and the older parts of Kettering). One can see the massive growth south, where a “new Dayton” has been created, and the river valleys and airport sort of separateing growth north into three fingers. Greene County would also show as a newer "new Dayton" to the east, similar to the growth south.

Deleting the older contingous areas one sees how growth was “north” and “south”, which have two suburban areas somewhat separate and disconnected from each other. It's noticeable that most of the built environment in the area post-dates WWII.

I-70 could be operating as the connecting feature between the “north” suburbs while I-675/75 is the connecting feature for the “South” (+ east) area. One can visualize how the Dayton Mall/Austin Road area is becoming the downtown for “South” .

What’s also noticeable is a large empty quarter. It’s really an almost empty quarter since Drexel, Trotwood and rural ribbon plats are there, but it did miss out on most of the postwar growth.

Applying two geographical models of urban form or growth; the concentric circle model (from the 1920s) and Homer Hoyt's sector model. These are two common models of urban geography.
One comes up with a diagram for Dayton, showing how there was a favored dector to the south (concept is sort of from Hoyt, bat also from Christopher Leinberg’s new book (The Option of Urbanism)" on land development and spraw) as well the empty quarter to the west. A new “favored quarter” has developed to the east due to Wright-Patterson driving development, especially after the early-mid 1980s.

I think the empty quarter phenomenon is fascinating. Most American citys just don't "stop growing" in one direction. It's something that's never remarked on here, but it is so obvious studying the maps and especially via this chronological look at how suburbia grew.

1 comment:

Bruce Kettelle said...

At some point the "Empty Quarter" will suddenly become appealing probably because of shorter commutes to downtown Dayton. Undeveloped land to the east and south is at least 15 miles (and 30 minutes during rush hour) away from the core. Land use and transportation planning for this outcome is minimal since most planners focus their projections on recent growth statistics which are near zero and in some cases negative. Are these areas in the "Empty Quarter" prepared for such an onslaught of development in the next ten or twenty years?