Photo by M.V. Jantzen on Flickr.

Cleveland Park resident Herb Caudill posted about the zoning update on the neighborhood listserv, and triggered a lively debate. On the issue of required parking, one resident wrote about “the growing hostility toward the automobile,” and said, “The need for parking is a reality of modern urban life.” Caudill followed up with this fantastic article, which we’re cross-posting with his permission.

The thing about the “anti-car/pro-car” frame is that it’s utterly useless when talking about urban planning and transportation planning. Most of us drive sometimes or all of the time. I drive, my wife drives, my friends and neighbors all drive.

Certainly some people are car-free by choice and sanctimonious about it; let’s ignore them for the time being. And while externalities like pollution and fossil fuels are important, they don’t need to factor into this conversation either. This isn’t about morality or virtue or sustainability.

The central fact about cars, from a planner’s perspective, is that they take up space. Lots of space. And this matters because space in cities (a.k.a real estate) is scarce and therefore expensive.

Cars take up space when they’re moving and they take up space when they’re parked, and even though they can’t be simultaneously moving and parked, you have to plan for both states and plan for peak demand; so you have to set aside some multiple of the real estate actually occupied by the car at any given time.

That’s just a practical observation about the spatial geometry of cities that doesn’t bow to my ideology or yours. And it would still remain true even if cars ran on nothing but recycled newspapers and emitted nothing but rainbows and unicorn tears.

In the past, our policy response has been to just set aside more and more space for cars: More freeways, more roads, more lanes on existing roads, more parking garages and surface lots. This approach hasn’t worked, and there are two very practical reasons why:

First, you can never build enough. There’s a phenomenon called “induced demand” that is very well understood by now. A new lane or a new freeway never reduces congestion in the long run: People respond to new capacity by driving more or by living or working in previously remote places, and you’re very quickly back where you started and have to build still more. The same phenomenon applies to increases in the supply of parking. It’s a game you can’t win.

Second, when you do make more space for cars you quickly start to crowd out any other potential mode of transportation, especially walking. All those parking lots and freeways and roads spread everything else out so that the distances become too great for walking. And the more you optimize any given space for cars the more hostile that space is for pedestrians. Very quickly you get to the point where it becomes impossible — or prohibitively depressing — to get things done on foot.

And this last fact has huge quality-of-life implications for human beings — not just because driving to a distant strip mall for a gallon of milk is less pleasant than walking to a corner store, but also because for many people driving simply isn’t an option.

Some people can’t drive because they’re not old enough, others because they’re too old. Some people are blind. Some people don’t know how to drive. Most of all, plenty of people can’t afford a car. And it’s really, really not fun to be in one of those categories and live in a place where you have to drive to get anything done.

The District government has very belatedly come around to the realization that instead of focusing narrowly on cars, we need to focus more broadly on mobility. Cars will always a big part of that, but one third of DC residents live in households that don’t own one, so it can’t be the only part.

Some drivers have reacted to that shift with outrage that they’re no longer the center of the universe, like only children who have acquired a baby sibling. That’s not a mature or reasonable or productive reaction. As DC’s population continues to grow, the population of cars can’t keep growing at the same rate. Not because cars are bad but simply because we don’t have room for them.

So we have to take steps to increase the market share of non-driving modes of transportation. That’s not a pro-car policy or an anti-car policy, it’s just a sensible response to the way the world is.

What does this have to do with zoning? Well, you don’t take “everyone drives” as a starting point or as an end point. As a matter of fact, not everyone can drive; and as a matter of principle, we want people to have other options. So we allow corner stores so people can run simple errands without driving. We allow alley dwellings and garage apartments so a few more people can live in walkable neighborhoods and near metro stops. And we stop forcing developers to build more parking than the market demands. These are very modest but obvious common-sense steps.

Meanwhile, I’m going to keep driving when I need to, and so are you, and that’s fine. Nevertheless it’s in all of our best interests for DC to make sure that that’s not the only choice we have.