New York City and San Francisco are also some of the most urban and mass transit-oriented areas of the US, which means walking is a default part of one's life i

New York City and San Francisco are also some of the most urban and mass transit-oriented areas of the US, which means walking is a default part of one's life instead of a leisure activity— getting through one's daily life means walking at least half an hour, and easily more. http://www.nytimes.com/2016/04/11/upshot/poor-new-yorkers-tend-to-live-longer-than-other-poor-americans.html http://www.nytimes.com/2016/04/11/upshot/poor-new-yorkers-te...