I apologize for the silence on this blog--and right in the midst of a series, on the commercial management of neighborhoods. We are in the midst of a cross-country move, from Washington, DC, to St. Paul, Minnesota; life has been upside down. I do intend to finish the series I began, but since I have been spending an inordinate amount of time in the car recently and thinking a lot about where I want (and do not want) to live, I will here give a more immediate post, on the cost of yards. Someday, perhaps, I will discuss the social costs; here I will only discuss the costs for the natural world.
To open, I'd like to acknowledge that my position is a little unconventional. In Washington, we often joked about the standard assumption that what an urban environment really needs is "dedicated green space." Indeed, I agree. But I would not extend this need as far as it is often extended. Even in the densest neighborhoods in Brooklyn (though perhaps not in some parts of Manhattan, the densest square miles in the United States), every brownstone and many apartment complexes have backyards and garden spaces. There are places for flower boxes out front (though, to be fair, in some neighborhoods flower boxes need to be kept out of range of unseemly types). There are trees in the sidewalks, huge parks, little playgrounds, neighborhood gardens, and triangle gardens caused by strange street patterns. (Indeed, Jane Jacobs emphasized the importance of using these odd spaces for natural beauty.)
Yet most Americans -- certainly those in Washington, a city of vastly greater greenspace than New York -- want more. They want a yard. They want a place to garden. Walking around St. Paul, I have been struck by the frivolity of the latter: add up all the space in my parent's upper-middle class midwestern neighborhood that is actually gardened, and, I think, you will find that Brooklyn is sufficient for the time and energy Americans have for gardening. But what of yards?
Jane Jacobs points out the irony of yards as environmental safeguards. Perhaps you need a mathematical mind to fully appreciate this, but every foot added to a neighborhood's average curb adds exponentially to the amount of countryside that will be paved over. Allow me to oversimplify in order to make a point. In our old neighborhood in Washington, the average family had about ten feet of curb space. (Actually, slightly more per house, but many houses had more than one family stacked on top of each other.) In St. Paul, let's say the average house has 100 feet of curb space. Now, if I need to go 20 houses down (to the market, or the park, or work, or wherever) in Washington that would be 200 feet, in St. Paul, it would be 2,000.
The most basic problem is that we will much more quickly reach our walking thresholds. Perhaps one is willing to carry a jug of milk no more than two city blocks before it seems easier just to drive. Whatever that threshold is, increasing the average lot size by a factor of ten means only 10% of what was formerly within our threshold will remain there.
(This is actually a bit more complicated, because yards, neighborhoods, and walks are all in two dimensions, not one. But we'll leave that alone.)
A problem subsidiary to this one is that as fewer and fewer things are within our walking threshold, our threshold is likely to decrease. This was something we often observed in Washington: those who are used to walking places consider eight blocks just a run around the corner, but when non-walkers come to visit, they consider the same distance to be unreasonable. They are used to driving. And thus that factor of 10 is quickly multiplied: not only are things ten times farther away, but people are less willing to walk a comparable distance.
And so, of course, as more and more things require driving, more and more people require cars (consider that in New York fully 50% of residents don't even know how to drive), more and more streets must be built, and more and more places will need parking lots. Dedicated green space means more concrete: you pave paradise and you put in a parking lot!
Now obviously, this math quickly reaches a saturation point. Even in the denser yarded neighborhoods of St. Paul, no one walks anywhere; you might think that once this point is reached, increased distances will be irrelevant.
But that is not the case. To appreciate why, think for a minute about the odd phenomenon (as a child, it drove me crazy!) of what happens when a stop light changes to green. At first glance, it seems that when the light changes, everyone should start driving. But in fact, when the light changes, the first guy starts going, but the next guy has to put some space between him and the car in front of him before he starts, and so on, so that, as we all know all to well, if you're even five cars back, the light may be red again before you even start creeping up toward it. Why is this? For the simple reason that the faster you're going, the more space you need between you and the car in front of you (and the cars to your sides, as well). In stopped traffic, you can be right on the guy's bumper, but that would be dangerous when you're moving; and a distance that's safe at 30 mph is quite unsafe at 60. A single car takes up far more space on a freeway than in downtown traffic.
This is another reason (in addition to the lowering thresholds for walking) that the yard-to-street ratio is exponential: adding a foot of yard to each house means adding a disproporionate distance that people must travel; and if people want to get there in a reasonable amount of time, they will need to drive faster, and thus take up more road space.
A third exponential factor is the flipside of the first: the more people drive, the more they get used to driving. If you're used to walking down the block for something, driving five miles seems like going a long way. If you're used to driving five miles, twenty five will seem less unreasonable. This, I'd like to suggest, is a big part of the SUV phenomenon. If you don't spend much time in your car, it's reasonable to have a small, slightly uncomfortable one. But if everywhere you go requires packing the family in for a half-hour drive, you get something big and plush (with a DVD for the kids!). The comfort of your car becomes increasingly important. (And honestly, SUVs are much more comfortable, and, truth be told, much safer. If you're going to spend all that time in your car, it makes sense to invest in something that will protect you.) In other words, increasing yardspace by a factor of ten means not only increasing drivetimes, but also increasing people's willingness to drive long distances, both for internal reasons (it seems normal to drive a long way to things) and for external reasons (people buy cars that make driving more pleasant).
A fourth exponential factor is the decreasing feasability of mass transit. This is an article in itself, but the simple fact is, putting bus lines and train lines out to the suburbs is stupid. Nobody wants to drive through ten miles of suburban traffic, park their comfy SUV in a big sunburned parking lot, then get onto a crowded train to take them in to where mass transit actually makes sense. Again, there's some math here. The area of a circle is pi times the square of its radius: in other words, adding a mile to the radial distance from you to center city means adding an exponential amount of area for mass transit to cover. It makes sense to have mass transit where everyone is close together; pi times ten miles squared is a reasonable amount of area to cover with buses and trains. But covering a circle pi times thirty miles squared is simply impracticible. (This is one of the ways that the new urbanism and other liberal projects are totally unreasonable.) The system becomes too complex, the drives are too long, the cost-benefit ratio skyrockets. Spreading people farther apart (with yards) massively increases the necessity of everyone taking their own car.
I'll cut this off before it becomes even more burdensome. The point is, a little "dedicated greenspace" exponentially increases the spaces that must be covered with roads and parking lots. (Not to mention those beautiful "green" spaces that buffer people from the freeways.)
Why does it matter? Three quick reasons. First, it means that people are increasingly far from actual nature. As more and more land is turned into exurbia, those who do not live in the exurbs must drive farther and farther to get to undomesticated places. And honestly, a yard is no comparison for fields and woods. Nor is a park really a good substitute, both because it can never be wild in the same way and because every park means that much farther that everyone must drive to get around it. And ironically, the farther people have to drive to get to the countryside, the more the countryside needs to be paved for people to get to it. Robert Moses built Jones Beach so that New Yorkers could enjoy Long Island. But he covered it with parking lots so that people wouldn't have to take mass transit. In our modern cities, where mass transit is no longer even practicable, every state park needs a massive parking lot.
The second problem is environmental. I am no expert on this so I can't say much of intelligence, but I know that the pesticides we put on our yards are far more damaging to the natural world around us than our normal lives; it's not the people, I think, who make the Mississippi unswimmable; it's the yards. I do know that dense living, because more of the transportation is done on foot, requires fantastically fewer resources; the statistic I've heard is that New Yorkers today use as much fuel as Americans in general did in the 1920's. That's a lot greener. And I know that it's more efficient to heat or cool a space when the space next to it is being heated and cooled rather than when it's surrounded by the great outdoors; energy bills go down all around with row homes and apartment buildings. And it would seem to me -- again, as an amateur -- that the land is more able to sustain the impact of human living if more of the land is left untouched. Even assuming that people produced the same environmental impact no matter how far out they were spread, doesn't it seem like concentrating all that impact on a few square miles would make it easier for the surrounding land to survive than if the impact hits a larger swathe? Greenspace is not 'green,' in the sense in which that word is now used.
And a third reason is that car culture means people don't spend much time outside anyway. If the goal is to give people some contact with nature, it probably makes more sense to promote a pedestrian lifestyle than to make people drive past yards and dedicated greenspaces (or, more likely, to drive on freeways so they don't have to deal with the greenspace).
The title of this post is the "cost" of yards. I intend this post not as a final word -- 'yards are bad' -- but as a factor to consider. If urban neighborhoods are decrepit, not family friendly, not affordable, or otherwise unliveable, than it probably makes sense to pay these costs and choose to live somewhere with a yard. But the basic conclusion is this: yards make us further, not closer, to nature.
(In postscript, I would like to note that the solution need not be coercion. The solution may be more negative -- lower taxes, lower regulations, fewer aids to the suburbs -- rather than positive, such as more services, or direct attacks on the suburbs. But this is a matter for another post.)