Via James Russell on Twitter, here’s a bottom-up map that was generated from analyzing 130 million commuter patterns and narrowing those trips into a series of “megaregions” around the country.
The end result, in multi-color glory:
And another one showing clear delineations:
Previously megaregions have been typically identified by an interpretative method that links large metropolitan regions through similar environmental and infrastructure systems, economic links and cultural similarities. These approaches are often based on a ‘best guess’ kind of approach, and do not rely on the analysis of large datasets.
Now Dr Alasdair Rae and his co-author Dr Garrett Nelson have developed an empirical approach to identify megaregions using a dataset of more than 4 million ‘commuter flows’ involving the travel to work patterns of 130 million Americans.
The data comes from five-years worth of data from the American Community Survey between 2006 and 2010. The yearly nationwide survey of 3.5 million employees asks where they worked ‘last week’.
Using algorithmic ‘community partitioning’ software developed by the Massachusetts Institute of Technology (MIT) and cloud computing powered by Amazon Web Services, these commuter flows were mapped out and revealed massive labour market areas across the US that form distinct megaregions.
“In addition to identifying broad US megaregions, we also conclude that there is no replacement for a common sense interpretation of any results generated through computational approaches. We believe the megaregions we identify are a true reflection of the economic geography of the United States but of course they need to be tested and validated in the real world for them to have real use.”
As you can see, the Twin Cities’ “megaregion” extends pretty far into Western Wisconsin, including Eau Claire, La Crosse, and Superior. To the West, it reaches about 1/3 of the way into North Dakota, though South Dakota escapes its clutches. Eventually the line gives way to one of the few megaregion vacuums extending over the Rockies.
I guess we already knew about the economic “watersheds” formed by different large urban areas. But it’s interesting to see actual bottom-up commuting data back it up.