The Essential Tension

I realize looking back on it that in this post I got a little distracted from the point I initially wanted to make (a hazard of blogging). But here it is. There’s a difference between a community that’s “drivable” in the sense that you could get around it primarily by driving, and a community that you would want to get around by driving. Nothing is stopping anyone from driving around in Manhattan and, indeed, a lot of people do it. And therein lies the problem. There are so many people driving around in Manhattan that it’s a big hassle (traffic) and expensive or time consuming (parking) and since so many trips are annoying and parking costs are so high, a lot of people don’t own cars in the first place. Conversely, there’s a difference between a community you could walk around in, and a community where walking would present itself as the best option for a large portion of trips.

And the sad part is that it’s difficult to build a community that serves both imperatives well. On a basic level, this is because of a straightforward conflict over space. To make driving appealing, you need to dedicate a lot of space to cars — wide roads and many parking lots. But to make walking appealing, you need to cram a lot of stuff into a small radius. And it’s hard to cram a ton of stuff into a given area if lots of space in that area is taken up by roads, curb cuts, parking lots, etc.

What’s more, there are a lot of tipping point effects. If you move into a non-poor neighborhood where most families own one or zero cars, then odds are there will be a bunch of retail and dining establishments in that neighborhood that are designed to cater to people who aren’t accessing them by car. Thus, you might consider eschewing car ownership and spending that money on other stuff. Which, in turn, helps drive the fact that an entrepreneur opening a business in such a neighborhood will make sure to design it to appeal to customers who aren’t driving there. But if everyone in the neighborhood is on a “one car per adult” model, then they’re probably going to do most of their shopping in stores that feature big parking lots and may be a little ways away. Given that, there won’t be much pedestrian-oriented retail in the neighborhood. So if you move to the neighborhood, you’ll want to stock up on cars and maybe scrimp on other stuff.

Consequently, it’s difficult to have it both ways. Indeed, it can even be dangerous. According to Christopher Leinberger’s research, a successful drivable suburb needs a floor area ratio that’s in the .005 to 0.3 range. By contrast, to create an area where people walk around a lot and there’s street life you need a FAR of at least around 0.8 (and for actual car-free lifestyles to be viable maybe as much as 1.5). Fall in the middle and you get someplace that just sucks — it’s crowded, but there’s nowhere to go and nothing to do.


Of course the good news is that while any given community probably does need to be fish or fowl in a way that presents the kind of choices that kind-hearted liberals generally prefer to avoid, it’s a very large country so it’s more than possible for a lot of places to feature walkable urbanism and a lot of other places to feature drivable suburbanism and people can just live where they like. Ideally, though, every major metro area would contain some neighborhoods of each kind because, obviously, people need to choose which region of the country to live in for reasons other than their preferred way of getting around.