Pasadena, Calif.

Abandoning grueling freeway commutes and the ennui of San Fernando Valley suburbs, Mike Boseman recently found residential refuge in this Southern California city. His apartment building straddles a light-rail line, which the 25-year-old insurance broker rides to and from work in Los Angeles.

Richard Wells is more than a generation older but was similarly attracted to the Pasadena apartment building. The British-born scientist retains what he calls a European preference for public transportation despite his nearly 30 years in California. Plus, he said, the building's location means, "I can walk to a hundred restaurants, the Pasadena symphony and movie theaters."

Messrs. Boseman and Wells embody trends that are dovetailing to potentially reshape a half-century-long pattern of how and where Americans live: The driveable suburb -- that bedrock of post-World War II society -- is for many a mile too far.

In recent years, a generation of young people, called the millennials, born between the late 1970s and mid-1990s, has combined with baby boomers to rekindle demand for urban living. Today, the subprime-mortgage crisis and $4-a-gallon gasoline are delivering further gut punches by blighting remote subdivisions nationwide and rendering long commutes untenable for middle-class Americans.