Christopher Leinberger planning guru and author of The Option of Urbanism: Investing in a New American Dream has a great post over at The New Republic taking aim at what he sees as a sometimes artificial divide between city and suburb. The key word is “sometimes.”

It’s no question that cities and suburbs have traditionally differed greatly when it comes to land-use and transportation policies. Cities are dense walkable and urban whereas suburbs are large spread out and purposefully not urban. In many places that characteristic divide is still quite present; however those traits are not nearly as steadfast as before. As Leinberger and countless others have proven people actually prefer to live in walkable mixed-use places because of improved quality-of-life. And many suburbs are therefore adapting.

Leinberger’s argument is that with these preferences now being more readily recognized by developers and officials the divide between city and suburb becomes more muddled. Places like Tysons Corner a mecca of sprawl are becoming urbanized to meet demand. Even further-out Loudoun County is embracing urban development around its upcoming Metrorail stations.

A vast majority of metro Washington’s population lives in suburban areas. Luckily as Leinberger points out “70 percent of the walkable urban places [in metro Washington] are in the suburbs.” The growth and demand for “urbanized suburbs” like Silver Spring and Arlington are hopefully indications that future growth in the suburbs is likely to be of the more transit-oriented (and therefore much more sustainable) type than old-fashioned sprawl.