A new report by the U.S. Bureau of Transportation Statistics finds significantly more young people think sidewalks, bike lanes, and local transit are important to quality of life than do older people. But the survey on attitudes about transportation found that all Americans find "major roads or highways," and "adequate parking in the downtown or business district" the most important element of "livable communities."

Ninety-two percent of 18-34 year-olds found sidewalks important, compared to 73 percent of Americans 65 and older. The gap was equally as wide on bike lanes -- with 73.8 percent of younger Americans saying they're important, compared with 51.9 percent of senior citizens.  On transit, there was a smaller but still hefty 14-point gap, 80.5 to 66.2 percent.

But 95.9 percent of younger Americans found major roads important and 91.5 percent of older Americans did, a much smaller differential.

Still, the survey findings represent a significant generational shift in attitudes about biking, walking, and transit.  Last year, Ad Age magazine documented a palpable change in driving habits among young people. Ad Age showed the number of American teens with drivers licenses has dropped since 1978  from half of all 16-year-olds to just a third, and from 92 to 77 percent of 19-year-olds.

The BTS  findings, which reflect a new set of questions in the BTS' Omnibus Household Survey (OHS), were derived from a sample of about 1,000 households in 2009. According to the report, "survey participants were asked to rate how important several transportation options or features were to have in their community, such as highway access, transit service, and bike lanes. "

"Livability" has come to have a certain set of meanings in the Obama administration, which include, at the top, access to more transportation choices. But in the American psyche, livability continues to mean having major roads and downtown parking. Over 94 percent of Americans ranked "major roads or highways that access and serve your community" as important, with "adequate parking in the  downtown or central business district" second most important, chosen by 89 percent of those surveyed.

Nevertheless, "sidewalks, paths or other safe walking routes to shopping, work, or school," and "pedestrian-friendly streets or boulevards in the downtown or central business district" were next most important, with 85.2 and 85.0 percent of Americans, respectively, ranking those services as important. "Easy access to airport" was fifth most important, at 83.2 percent.

Generational shifts can be difficult to interpret.  In general, voter attitudes tend to track age -- and people's opinions change as they get older.  So, for example, older voters tend to be more fiscally conservative and more anti-crime than younger voters.

But there was a huge exception to that rule recently.  On gay marriage, voters have held on to their beliefs even as they age, so that as the a startlingly higher percentage of Americans support gay marriage today than did a decade ago.  New York recently voted to legalize gay marriage.

The report also found gender shifts, with women generally ranking "pedestrian friendly" streets and sidewalks more highly than men.

The BTS survey of perceptions was added to its roster of reports, which tend to include things like counts of airline employees or freight cargo weight.