(USA TODAY) -- The dismal economy and skyrocketing gas prices may have accomplished what years of advocacy failed to: getting more people to stop driving solo. The share of workers driving to work alone dropped slightly from 2010 to 2011 while commutes on public transportation rose nationally and in some of the largest metropolitan areas, according to Census data out today Thursday.
Group commuting -- riding buses, trains, subways or sharing cars or vans -- rose from 2005 to 2011 in more than a third of 342 metropolitan areas for which data exist, according to a USA TODAY analysis.
About two-thirds saw jumps in residents using public transit. The share driving to work alone dropped in about two-thirds or more than 200 metros.
New York City, by far the national leader in mass transit use, saw a two-percentage-point jump. Now, almost a third of residents in the New York metro area use public transportation.
Ride-sharing "a lot of times is a response to higher gas prices," says Eddie Caine, who heads the van pool program for Valley Metro, Phoenix's regional transportation agency, "but once people try van pooling, they tend to enjoy not having the stress, saving money and they make friends."
The national average price for regular gasoline is $3.85 a gallon, according to AAA and the Oil Price Information Service. That's up from $3.72 a month ago and $3.59 a year ago. The record is $4.11 set in July 2008.
The Phoenix agency just added bike racks to its vans for people who don't want to drive to their pick-up points.
This week, the American Public Transportation Association reported the sixth consecutive quarterly increase in ridership -- up 1.6% in the second quarter. Rail showed the biggest jump. Several public transit systems in small and large cities (Ann Arbor, Mich., Boston, Oklahoma City) reported record ridership.
Almost 60% of trips on mass transit are work commutes. The surge in group commutes is showing up in some areas where van pools shuttle employees from train stations or suburbs to job centers. Overall, the percentage of workers carpooling held steady at 9.7% but is still slightly below pre-recession levels -- a likely effect of high unemployment in sectors such as construction and manufacturing.
In California's thriving Silicon Valley, 31 shuttles provide transportation to work sites from 19 train stations, and ridership is up 30% over last year in San Mateo County, says Christine Dunn, public information officer for the county's bus system and the Caltrain San Franciso-to-San Jose line.
"In this area, I think people have become increasingly concerned about the environment," she says.
A survey by the agency shows that interest in helping the environment has risen 35% since 2003, Dunn says. High gas prices and more employer incentives are contributing factors, she says.
Generational changes are shifting attitudes, too.
"You have an aging population of Baby Boomers, the bulk of whom are winding their years in the work force, who have started to explore other ways of getting around," says John Robert Smith, president and CEO of Reconnecting America, a non-profit organization that focuses on transit-oriented development. "At the other end of the spectrum, you have the millennials, who many recent polls have shown do not have the same urgency to get their driver's license."
Driving also gets in the way of mobile phones, e-readers and other technology.
"This is a generation that texts, and you can't do that while you drive," says Virginia Miller, spokeswoman for the public transportation association.
Alan Pisarski, author of a series of Commuting in America books, is skeptical.
"I may be old-fashioned here, but I find it hard to believe they take transit to text," he says. "Is this a product of the current economy or is this a new normal?"
The new 2011 Census data show that the economic downturn continues to affect birth rates, especially among young women.
Fertility rates dropped for virtually every racial and education group, says Kenneth Johnson, demographer at the University of New Hampshire's Carsey Institute.
The worst may be over for Florida, Johnson says. The state gained people from other states for the third straight year after two years of losses. Other Sun Belt boom states are still struggling. Nevada continued to lose people to other states, but Arizona eked out a small net gain.
The nation added just 430,000 households, half the average rate of the last decade. Average family size under one roof rose for the fifth straight year, to 3.25 as young adults stayed or came back home.
The marriage rate fell again. Median age at first marriage rose to 28.9 for men, 26.7 for women. Since 2005, marriage age has risen by almost two years for men and 1.4 years for women.
The rate of people who moved fell again, to 14.6%, although the rate for interstate movers inched up to 2.3%.
The share of immigrants from Latin America has dropped to 52.6%, as the slow U.S. economy and tighter border security have cut migration from there. Bigger shares are coming from Asia and Africa.