At the risk of exposing my inner geek (I know, some of you are itching to point out it’s not that buried) I will reveal that I could literally spend hours at this website, the Housing + Transportation Affordability Index.  There is a lot of talk about how expensive it is to live in the city but often when people speak of this they are only talking about the costs of housing and not also the costs of transportation- which can be significant.  The H+TA website, developed by the brilliant folks at the Center for Neighborhood Technology, graphically contrasts the difference between measuring just the cost of housing and measuring the cost of housing AND transportation.  The example they use on the homepage is of Minneapolis/St. Paul metro region, below.

Basically, the blue areas are expensive and the yellow are less so.  The map on the left shows housing costs as a percentage of income, with 30% as a threshold.  The map on the right shows the combined costs of housing and transportation, with 45% as the threshold.  The difference is pretty striking, when you consider the costs of transportation the denser areas are far more affordable places to live.  But I know less than nothing about this area so I decided to look closer to home.

Here’s a look at my neighborhood, Ft. Greene-Brooklyn, where you get a finer grained example of a similar effect.  The grey block on the upper left is Ft. Greene park and the map on the left shows clearly that housing near the park is more expensive, no surprise. But adding the costs of transportation you see that some blocks close to the park are more affordable and, of course, some blocks near transportation are more affordable as well.

I then looked at the suburban neighborhood I grew up in outside Seattle, Washington and here you see a kind of inverse version of the same concept.  On the right hand side of the maps you can see the edge of Lake Washington.  The big blank spot in the middle is, of course, a shopping mall.  On the left everything looks fine- an inexpensive place to live.  But when you consider the costs of transportation you see that living next the mall (as I did) is only 10% less than living next the lake (which I decidedly did not.)

CNT has noted that the state of Illinois has adopted H+T as a planning tool.  Expect this sort of data to play a big role in municipal planning around the country in the years ahead.