> This is something that certain cities have understood for many years. Chicago
There is a big contradiction here, I haven't really seen walkable streets in Chicago (lived there for a year and a half). When I think of an American city with walkable streets I think of Boston for example.
Unless you lived in some far-out neighborhood and never went downtown, I really have a hard time believing you. I lived there ten years, after growing up in New York, and it was very walkable. I ended up getting rid of both of my family's cars because we could walk or CTA everywhere.
London and Paris also have large streets made for cars, and also has lots of streets that are empty at night. Even the Champs Elysées and Oxford St will be empty at certain times during the week.
Oxford St wasn't made for cars (horse carriages rather) and will likely be closed to traffic in a few years. There were some projects in the 70s-80s to make the city more car-friendly (mainly via one-way roads) but they're about to reverse that to slow down traffic. One of the busiest junctions in the city (bank) has already been closed to all traffic except buses during the day.
Having slow traffic helps pedestrians and increases the incentive to use the tube instead of a cab or car.
I'm mostly comparing to european cities. Chicago is definitely more walkable than a lot of cities, but it's nothing like european cities where you can walk around for hours and still be amazed at how much life there is around you.
There is a big contradiction here, I haven't really seen walkable streets in Chicago (lived there for a year and a half). When I think of an American city with walkable streets I think of Boston for example.