CHICAGO — High gas prices are getting most people down these days — unless, perhaps, they live in San Francisco.

The city was named the country's most walkable, according to a list released last week by Walk Score, a Web site that assigns grades to addresses based on the proximity of amenities surrounding them. Chinatown, the Financial District and Downtown were the most walkable neighborhoods in the city, according to the site.

New York followed at a close second, mainly due to the high walkability of neighborhoods including Tribeca, Little Italy and SoHo.

These days, the extent to which drivers can keep cars parked isn't just a perk; in an era of $4 gas, people are examining transportation costs when deciding where to live, as noted in a news release announcing the list. While people were fine with living in far-out suburbs when gas was cheap, many are no longer willing to keep driving out from a city's core until they qualify to buy a home, people in the real estate industry say.

"Most Americans agree we will never see cheap gas again," said David Goldberg, spokesman for Smart Growth America, referring to a Harris Interactive poll from December that found 92 percent of participants thought gas prices are likely to rise in the coming years. Smart Growth America is a coalition of organizations working to improve the ways communities are planned and built. Goldberg also serves on Walk Score's advisory board.

And the Center for Neighborhood Technology recently released research that showed people who live near transit, jobs, schools and stores spend up to $2,100 less a year on gasoline than those who live in outer-ring suburbs, where more driving is required.

The center also has a housing and transit affordability site that allows people to pull up maps that illustrate how much gas costs are affecting household budgets.

Americans, Goldberg said, are "starting to make decisions, big life decisions, based on the assumption that cheap gas is not part of the future."

The desire of Americans to be less car-dependent is leading real estate agents and developers to point their clients to sites such as Walk Score, said Mike Mathieu, founder of Front Seat, a civic software company that operates the site. Greg Waring and his fiancee used the tool in their recent home buying process.

For the couple, the closeness of amenities to the home was probably the most critical factor when choosing a new place to live in Seattle. After living in Chicago's Lincoln Park neighborhood — one of Chicago's most walkable areas, according to Walk Score — they decided to search for another home where they could park the car on the weekend and walk, ride their bikes or take public transportation where they needed to go.

The price of gas wasn't a big motivator for them.

"We were thinking this way when gas was $1.99 a gallon," Waring said. "For us, it's about quality of life ... who wants to spend time sitting in traffic to go to a local restaurant or bar or whatever when you can have great things that are in your neighborhood?" he said.

The convenience of walkable neighborhoods has been appealing to baby boomers and single-person households, Goldberg said. Others are attracted by the health aspect; when people can run their errands without a vehicle, they can sneak in needed exercise, he added.

While acknowledging that people probably won't want to give up their cars completely, Goldberg said it's quite possible that neighborhoods that allow residents to be less car-dependent will become the new norm for many Americans in the coming years.

"We're not talking about everybody moving downtown," Goldberg said, adding that even in cities that aren't very walkable there are neighborhoods that are friendlier to pedestrians.

Atlanta, for instance, has a reputation for being "the poster child of sprawl," he said. However, there are places nearby, like Decatur, Ga., that offer amenities and transit options without being a high-density neighborhood, he said.

To create more places that allow people to leave their cars at home, there needs to be a shift in how transportation funds are used, said Scott Bernstein, president of the Center for Neighborhood Technology. Mass transit options are gaining in popularity as gas gets pricier, and more government money will need to be put into improving those systems and making them more efficient, he said.

"What happened is we started investing in a system of streets and highways that made it easier for people to own personal vehicles," Bernstein said.

But there may be big changes afoot, as gas prices rise and people demand solutions, he said.