When Shaun Yandell proposed to his long-time girlfriend Gina Marasco on the doorstep of their new home in the sunny suburb of Elk Grove, California, four years ago, he never imagined things would get this bad. But they did, and it happened almost overnight.

Yandell’s marriage isn’t falling apart: his neighborhood is.

Devastated by the subprime mortgage crisis, hundreds of homes have been foreclosed and thousands of residents have been forced to move, leaving in their wake a not-so-pleasant path of empty houses, unkempt lawns, vacant strip malls, graffiti-sprayed desolate sidewalks and even increased crime.

In Elk Grove, some homeowners not only cut their own grass but also trim the yards of vacant homes on their streets, hoping to deter gangs and criminals from moving in…

While the foreclosure epidemic has left communities across the United States overrun with unoccupied houses and overgrown grass, underneath the chaos another trend is quietly emerging that, over the next several decades, could change the face of suburban American life as we know it.

This change can be witnessed in places like Atlanta, Georgia, Detroit, Michigan, and Dallas, Texas, said Leinberger, where once rundown downtowns are being revitalized by well-educated, young professionals who have no desire to live in a detached single family home typical of a suburbia where life is often centered around long commutes and cars.

Instead, they are looking for what Leinberger calls “walkable urbanism” — both small communities and big cities characterized by efficient mass transit systems and high density developments enabling residents to walk virtually everywhere for everything — from home to work to restaurants to movie theaters.

The so-called New Urbanism movement emerged in the mid-90s and has been steadily gaining momentum, especially with rising energy costs, environmental concerns and health problems associated with what Leinberger calls “drivable sub-urbanism” — a low-density built environment plan that emerged around the end of the Second World War and has been the dominant design in the U.S. ever since.

Changing demographics are also fueling new demands as the number of households with children continues to decline. By the end of the next decade, the number of single-person households in the United States will amost equal those with kids.

Most Western nations never got round to aping exurbanite Levittown. They never destroyed rail systems. Trashing inner city communities in the name of Urban Renewal never achieved a political mandate.

More than ever before, the cost of energy and transport may begin to govern living trends in the United States – again.