On the subject of development and the Purple Line, check out Brad Plumer’s post, covering a Brookings panel on the issue. It reads in part:

Another panelist, Chris Leinberger, a Brookings expert on development who comes at things from a real-estate perspective, countered that that was a much too narrow perspective. Leinberger follows the—somewhat controversial—view that transportation actually drives development (rather than the other way around), and that transit projects should be thought of less as about moving people, and more as about creating value in a metro area. His take was that middle-class people will take rail, but rarely take buses, which unfortunately carry the stigma of poverty, and hence, developers are much more likely to invest around rail stations than bus stops. (This may not be an ironclad law, but, alas, the United States has relatively few examples of successful BRT systems a la the famous one in Curitiba, Brazil).What’s more, Leinberger assured the audience, development will follow new transit lines, because there’s colossal pent-up demand in this country for transit-oriented development. By his count, 30 to 50 percent of residents in most U.S. metropolitan areas want to live in a walkable urban environment—a trend that’s, in part, fueled by the growing prevalence of single and childless couples, who will constitute a whopping 88 percent of household growth through 2040. Trouble is, he estimates that there are only enough walkable areas to satisfy about 5 to 10 percent of residents, which is why transit-oriented areas are so exorbitantly expensive. (Incidentally, the boom in childless households is one reason why development in D.C. could start to expand beyond the long-privileged Montgomery County and toward the northeast D.C. metro area and suburbs, even though the latter have long been hampered by inferior schools.)

I’m wondering — is the view that transportation drives development controversial? There shouldn’t be a rather there, of course; existing development patterns do shape transportation planning and construction. But I wonder on what basis anyone could argue that development doesn’t respond — strongly — to the transportation structure along which it occurs? It would be much more difficult to take the opposite view, actually, and explain why the construction of a major highway or rapid transit line that acted to heavily alter the cost basis of transportation options didn’t influence behavior, and therefore development.

Now what one might argue is that infrastructure and land-use appear to be jointly correlated because both are dependent upon political opinion and institutions. For instance, if we compare Fairfax and Arlington counties, we can use local politics to explain mid-century development patterns, the different choices made regarding new highway and transit construction in the 1950s and 1960s, and the diverging way that land-use subsequently changed around those new arteries.

But it’s probably best to understand that there are causal relationships in all directions.