Regional commutes as a way to define community

Garret Nelson had an idea and he is quite happy to talk about the results: The idea: Map the commute of every person in the United States to see how one can defined community, a problem that has vexed geographers for a long time. Or in the words of Nelsons dissertation: "an empirical approach to detecting and defining megaregions" considering "the relational, flowing concept of geography and put it to use in service of delineating coherent, bounded regions".

Nelson's commuter map 

That isn't something one can do on a laptop at home. Mr. Nelson now a post-doctoral fellow in the Department of Geography and Society of Fellows at Dartmouth College did this on an Amazon super computer large enough to digest all the census data and graph it over the American landscape. Like MIT's Neri Oxman's depictions of bio-mimicry which wound up in the MoMa, Nelson's maps are very beautiful and may well become the object of an art exhibit as well.

Nelson is a geographer not an architect, but he spoke Thursday in MICA's Brown Hall invited by Baltimore AIA as a part of the spring lecture series. This represents a departure from the traditional format of AIA's lecture series of showing pretty slides of architecture and broach more intellectual topics instead, an innovation already tested by the ambitious young lecture committee during last yera's series. This year's lecture umbrella topic is migration. "We didn't know how timely the topic would become when we picked it last year",  said committee chair Katherine LePage. The series covers in four lectures explorations of "conflict-driven migration, climate change migration, regional migration and interplanetary migration to Mars" (program paper).

Nelson is interested in the ways social change and landscape change are intertwined. He talked about the two-way connections between the landscape and society, about technology driven maps like his commuter patterns which are factual and data driven ("the computer made this") and "mind-maps" that are subjective, emotional and much more difficult to depict. Between the two one gets a dialectic relationship between interconnections on the one side ("flows, relationships, links") and discontinuities on the other ("groupings, borders, identities"). Nelson explained, although historic local definitions like "Boston" or "Cambridge" really mean nothing any more in a region that is stitched together by transportation and information networks with people and the entire economy connecting in a much larger unit, people in their minds still cling to the much more local patterns. "Bostonography" is a popular local website about that geography.

“Boston, the city directly at hand, is unique in character among American cities, being both vivid in form and full of locational difficulties.” (Kevin Lynch, The Image of the City, 1960)

The same can certainly be said about Baltimore. Nelson noted that "the sense of belonging, it is hard to change.Even if old borders are declared irrelevant that doesn't obliterate them" Certainly a point of acute relevancy.

The more thoroughly one is acquainted with the social and geographic facts in any area, the more keenly one becomes aware that unity and differentiation go hand in hand. (Lewis Mumford The Culture of Cities,1938 from Nelson's presentation)

In his dissertation Nelson explored the problem of what size geographic areas are appropriate for community planners to deal with when trying to encompass a total set of relationships that make up a “single” place. His commute maps show one result of this investigation. One would expect that a map of commutes would show a wild and thick patch of lines all across the United States, everybody knows that Americans tend to commute all over the place and over long distances, about twice as far as Europeans travel, a result of housing and job sprawl. But that is not what Nelson's maps showed. Instead the map was clearly organized into the major population centers with some type of starburst pattern. Nelson saw this immediate commuter generated result but wanted to clean it up further by cutting off the extreme commutes and using algorithmic community portioning software that isolates the connections between the census tracts. For example, he found that 97% of 4.319 million commute trips in the Baltimore Washington area originated and ended in a well defined geographic area which he dubbed the Chesapeake Region.

Commute patterns of the "Chesapeake Region"

Everybody in the region knows that the people of Baltimore and Washington or the northern Virginia suburbs don't feel they have much in common. They strongly identify with their States or their cities or counties. Even Montgomery County and Prince George's identify themselves less as the suburban Washington communities that they are but as the wealthiest county in the nation (Montgomery) or one of the the wealthiest majority African American counties (Prince George's).

Beyond the empirical and descriptive work of “discovering” new kinds of woven-together geographies lies the political and social work of making people feel as though they belong to new forms of community (Nelson)

The Chesapeake Region and five subregions

Certainly a desirable outcome. Nelson was cautiously optimistic that a data and information based approach may alter people's perceptions. How much is at stake can be seen not only in the need of a unified approach to metropolitan issues (such as the Bay cleanup) but also in the much larger current US and overseas political landscapes.


Klaus Philipsen, FAIA

An Economic Geography of the United States: From Commutes to Megaregions

Nelson's AIA presentation and maps
National Geographic Article