I'm sure people in the US would love to walk to work, but the layout of US cities doesn't lend itself to that. People tend to live pretty dang far from where they work in the US.
And then when I -did- live close to work (about 2 blocks) I had to cross the town's main street, where I was catcalled about every day and on multiple occasions had a man follow me home even after telling them politely each time that I was not interested. Horray. People here don't walk. So you stand out. When I was in the city I could wear a big heavy coat and most people will ignore you because you look poor/ugly, here even in my most ratty coat people still followed me...ugh.
In other countries, many many more cities.