city, state and federal policies that for more than half a century encouraged suburbanization and car use -- from mortgage lending to road building -- are gradually being diluted or reversed. "They created what I call a culture of 'automobility,' and arguably in the last 5 to 10 years that is dying out," Ms. Sheller said.
New York's new bike-sharing program and its skyrocketing bridge and tunnel tolls reflect those new priorities, as do a proliferation of car-sharing programs across the nation.
A study last year found that driving by young people decreased 23 percent between 2001 and 2009. The millennials don't value cars and car ownership, they value technology -- they care about what kinds of devices you own, Ms. Sheller said. The percentage of young drivers is inversely related to the availability of the Internet, Mr. Sivak's research has found. Why spend an hour driving to work when you could take the bus or train and be online?
From 2007 to 2011, the age group most likely to buy a car shifted from the 35 to 44 group to the 55 to 64 group, he found.
"Different things are converging which suggest that we are witnessing a long-term cultural shift," said Mimi Sheller, a sociology professor at Drexel University and director of its Mobilities Research and Policy Center. She cites various factors: the Internet makes telecommuting possible and allows people to feel more connected without driving to meet friends. The renewal of center cities has made the suburbs less appealing and has drawn empty nesters back in. Likewise the rise in cellphones and car-pooling apps has facilitated more flexible commuting arrangements, including the evolution of shared van services for getting to work.