What kind of city would you like to live in?

Of all the great changes America has undergone in its history, the urbanization of the late 19th and early 20th centuries was certainly one of the biggest. Less remarked-upon, but no less important, was the de-urbanization of the late 20th century, when everyone moved out to the 'burbs. A third great transition may now be underway, as we figure out how to re-urbanize our country for an age of high gas prices, high population, and house price that may not go up forever.

If we're smart, the key feature of the New America will be walkability.

Via Yglesias, Ben Adler writes the best article I've seen in a long time on the subject of walkability. The way most cities are built these days, we're not really able to walk from one place to another, so we use our cars. This results in most American cities and towns being incredibly boring, since chance meetings (with people you know or with friendly strangers) are an important source of pleasure for the social animal that is humankind. It also results in eveyone becoming a pasty, obese slug from sitting around in an air-conditioned coccoon every day instead of using the transportation method God gave us (I'm looking at you, guy in the mirror). We're becoming a nation of lonely Jabba-the-Hutt look-a-likes, and city planning is to blame.

The key villain in the story, it seems, is zoning. Separating residential and commercial space forces you to drive between the two. That means that both residential neighborhoods and shoppng districts must be built with tons of parking. That means strip-malls, strip-malls, and more strip-malls.

The alternative, though, as Yglesias points out, isn't necessarily to herd people back into the inner city. Nor are trains a cure-all. A new type of town is being built that combine some of the best features of suburbs (quiet neighborhoods and big houses) with the best features of cities (walkable shopping districts). The key is to allow mixed residential-commercial space, and to get rid of huge parking lots.

Ben Adler gives an example:

Developer Joe Alfandre built Kentlands, a landmark exurban development in Gaithersburg, Maryland, 20 miles north of D.C., because, he says simply, "I'm not enamored with subdividing strip suburban development."...Since opening 20 years ago, Kentlands has become the most desirable place to live in its town...

Much of Kentlands is taken up with large, expensive-looking, single-family homes. But they are close together, so that the town has sufficient density to support walking and transit use. The houses vary in architectural style, but they have one common quality: They are not hidden behind a giant garage. Many of the homes have ample parking, but it is set either behind the house in an alleyway or alongside the house down a narrow path. Likewise, every tree-lined block has a sidewalk on both sides. There are cars parked along the road, creating a buffer between people and the moving cars and helping to slow traffic. The neighborhood is filled with little pocket parks and playgrounds, and I met parents with young children playing in them. The town has a central square lined with elegant brick row homes around a green space with a public swimming pool. Noticeably absent are the gigantic parking lots that make walking an unlikely choice in most suburbs.

In addition to demonstrating the commercial viability of new urbanism, Kentlands is a case study in the symbiotic relationship between walkable street design and mass transit. The construction of a walkable community generated such demand for transit that one existing bus was quickly rerouted to serve Kentlands and another was created in 1997. "Kentlands wasn't built around transit, but once it was built, it was so dense that it has easily adapted to that," Alfandre says.

The most essential innovation of Kentlands is that it contains shopping integrated with housing. Tiffany Donovan, a mother walking her children home from the playground, tells me that she walks with her husband to a French restaurant "because who wants to drive home after a glass of wine?" Most parents also walk their children to the local elementary school (which is named, naturally, after environmentalist author Rachel Carson). "It's a great place to grow up," says Matt Ficke, a University of Maryland student who grew up in Kentlands. "Everyone walks everywhere. It's perfect for trick or treating because all the houses are close together."

There are not only families with children in detached homes, there are single people in their 20s living above stores and elderly people living in the taller apartment buildings. This kind of mixed-age development will be in especially high demand as demographic trends, such as the empty-nests of aging baby boomers, lead to an increase in childless households. (All emphasis mine)

The age aspect is important. Young people want to live in a densely populated place where they can meet other young people to be their friends or mates. Parents want to raise their kids in a quiet, safe environment with lots of space for the kids to run around. And old people want to live close to their friends. As things stand, we have an equilibrium where young people get mugged in the street, old folks are forced to move into "retirement communities" while they're still healthy, and parents are isolated and bored out of their skulls. It doesn't have to be this way.

Now is the moment for "New Urbanism" to spring into action, because high gas prices (which will return as soon as the depression lets up) have made drivers feel the pain of every mile. But it would be sad if our "strip-mall suburbs" were just replaced with "train-station suburbs" of Japan - lonely concrete islands of high-rises connected by mass transit to giant indoor malls. New Urbanist towns give us a third way out, but building such places requires planning and coordination. And we won't have planning and foresight unless the average citizen is well-educated about the kind of alternative that's available. Once people find out about the walkability and the New Urbanism, they'll put pressure on their local governments to deliver. We just have to tell people what they're missing.