As US population grows inexorably toward 300 million, there are two visions for the future of American towns and cities. Although very different, each seeks to create a sense of community, a sense of place where none existed before.
One focuses on downtown areas – often run-down, sometimes left as polluted industrial "brownfields." This new kind of urban renewal is seen in places like the trendy Pearl district in Portland, Ore.
The other vision – the most dominant one – is found among the tile-roofed homes mushrooming outward from the nation's fastest-growing city, Gilbert, Ariz., a Phoenix suburb. As recently as 1970, there were fewer than 2,000 people in this former agricultural town once called the "Hay Capital of the World." Today, the population is some 180,000; it's projected to peak above 300,000.
Five years ago, Gilbert had two automobile dealerships; today it has 17 – including, as Mayor Steven Berman proudly points out, "the third largest in the country." Five years ago, it had no hospitals; today there are two, and a third one is under construction. The whack of framing hammers and the buzz of power saws resound in new neighborhoods pushing out into those former hay fields.
Get used to it, says demographic trend-watcher Joel Kotkin.
"The sprawl is going to happen," he says. "You've got 100 million new people [since the US topped 200 million in 1967], they've got to go somewhere, and most don't want to live in the city. End of story."
Public opinion bears this out. Just 13 percent want to live in a city, 51 percent in a suburb, 35 percent in a rural community, according to a 2004 survey by the National Association of Realtors and a group called Smart Growth America.
"If you look at the survey data, even the nice cities are losing population," says Mr. Kotkin. "It's San Francisco, Boston, and Minneapolis, not just Cleveland and Philadelphia. The population growth of even the most robust cities is much less than the surrounding areas."
Still, most people need to work and not everyone can do it from home, although that's a growing trend. That means that most people need to live not too far from where their jobs are.
The idea, then, is to create what many planners and officials call edge cities or micropolitan areas, galactic cities, or technoburbs. These places are largely self-contained, with many jobs for local residents, most of whom would not have to be commuting long distances.
That would be Mayor Berman's dream for Gilbert. "Our goal is to build a town that everyone would want to live in," he says. "Not a resort town or a finance center, but a home town."
Finding its own identity amid the sprawl of Phoenix may not be easy.
"I have a theory that if they dropped you at eye level into any of these towns, you couldn't tell the difference," says Jay Butler, director of the Arizona Real Estate Center at Arizona State University. "Gilbert really is no different from [the nearby towns of] Chandler and Mesa. The homes look alike, the SUVs look alike, they all have a Costco."
But there are limits to such growth. In a state where 84,000 new homes were built last year – 7,000 a month – a major concern with such population growth is water.
"It's the issue everyone talks about and believes could be the ultimate limit on future growth," says Rita Maguire, president of the research organization ThinkAZ in Phoenix. "But very few people have a grasp of the real situation. The subdivisions are being staked out one after another with no time for comprehensive planning."
One thing that newcomers say attracts them to such new communities – especially in the West, where much of US population growth is happening – is the nearby mountains and recreational opportunities. But that can have a downside as well.
Every day, the US loses 6,000 acres of open space to development – nearly 4 acres a minute. Much of that loss is near national forests and other public lands.
"Our land development is outpacing population growth, especially in rural areas where the pattern of growth is low-density, dispersed housing," Dale Bosworth, chief of the US Forest Service, wrote recently. "Counties with national forests and grasslands are experiencing some of the highest growth rates as people move to be close to public lands."
Then there's the other vision for US towns and cities: urban revitalization.
Professional planners often joke that Americans dislike both major US development trends: sprawl and infill. If metropolitan Phoenix typifies the first, Portland aspires to the second.
Because Portland doesn't have the wide open spaces of Arizona – it's hemmed in by the Columbia River on one side and well-established suburbs on the others – the city's growth possibilities are limited. That's one reason its focus is on existing neighborhood potential.
The best known effort is in the Pearl District, a downtown former warehouse area that's being transformed into condos and apartments, often built above retail shops, galleries, and other businesses and offices, with transit facilities, grocery stores, parks, and other amenities nearby.
City officials have planned for 5,000 housing units in the district – roughly a 2 percent increase in the city's housing stock. About 1,000 of the units are meant to be "affordable" to those with an annual household income of less than $30,000.
So far, about two-thirds of the planned housing units have been built, including 800 of the affordable ones, says city commissioner Sam Adams. To preserve affordability, a local nonprofit organization owns the land on which the housing is built.
"We've mixed affordable units with the most expensive, and we've made sure the quality for all of them is the same," says Mr. Adams. "But we need to do a better job of building housing that's suitable for families with children," he adds, because most such units have only one bedroom.
"We've worked really hard to design our city so that density is viewed as an amenity as opposed to a detraction from our livability," says Adams. Building around public transit, including light rail and modern street cars, has been one of the most important aspects here.
Portland may be a leader among US cities facing demographic shifts, but it is not without major challenges. Among these: economic development that creates new jobs in an era of increasing globalization; finding a financially viable way to extend public transit into more neighborhoods to reduce downtown auto traffic; and dealing with a rapidly aging infrastructure. Portland has a 600-mile backlog in street maintenance as well as many bridges needing repair.
"What I worry most about for Portland is that our high rankings as a city – and we're a wonderful city; don't get me wrong – mask some serious underlying negative economic trends," says Adams, a former mayor's aide.
How fast cities and the nation grow also has an impact on how people live. For example: One reason the US is virtually the only developed nation projected to grow rapidly during the next few decades is its high fertility rate. Indeed, the US has the highest teen birth rate in the industrialized world: 22 percent of all women become mothers before age 20.
By contrast, the rate is 4 percent in Sweden, 6 percent in France, and 11 percent in Canada. At the same time, 35 percent of US births are unplanned, a figure Population Connection president John Seager finds "astonishing."
"Our fertility levels are as high as they are in part because of a significant high fraction of births out of wedlock," says University of Pennsylvania demographer Samuel Preston.
Population growth and land development will continue to affect where and how Americans live. So will things like increasing house sizes, commuting distances, automobile ownership, and other indicators of affluence.
All of these things are interconnected. Growing affluence means more people can buy a new house or an extra car for commuting purposes. Depending on your point of view, suburbs or small towns like Gilbert that have become booming satellites of a nearby big city indicate sprawl or they offer new opportunities for individuals and businesses.
Brian Brown and his family moved to Gilbert from Orange County, Calif., two years ago.
"I was living in an 800-square foot apartment paying $1,100 a month rent," he says as he keeps an eye on his year-old son playing on a jungle gym in Freestone Park. "But here, we could afford a 2,000-square-foot house for the same price."
The move did mean a 54-mile commute to his job at a Trader Joe's store in Glendale way on the other side of Phoenix. In fact, commuting in fast-growing suburbs can be a major challenge.
Although Gilbert has only one-third the population of Portland and significantly fewer people per square mile, it has longer average commute times: 28.6 minutes vs. 23.1 minutes. Recently, Mr. Brown was transferred to a closer store in Mesa.
Has the family found a sense of community here? He pauses before answering: "Not yet. If anything, that is one of the hardest things for us. In California, everything was at our fingertips – restaurants, shops, entertainment. We really miss that a lot."
That's the challenge for places like Gilbert trying to maintain community as its population soars. And over the coming decades, experts wonder whether this kind of growth, based on the automobile, is sustainable.
The key question, says Kotkin, is: "Do we manage this growth in an intelligent way and figure out how to make it environmentally benign?"
"The other way is to try and become like Europe, stop having babies and stop having immigrants, and become kind of a museum society," says Kotkin, who extols the economic and social virtues of what he calls the "new suburbanism." "That is not in the nature of Americans."
• Next: What's ahead as the US grows toward 400 million people? Previous installments ran Sept. 12, 19, and 26.