Check out Bangkok's Skyline rail, there's multiple levels to it and generally a walking level beneath the train, at least in the popular areas of town.

I like walking when I'm not in a hurry and the weather is nice, but the weather usually isn't nice in most parts of the country (the US West Coast is an exception to that). I'm looking at moving to a southern state now and the only reason I'm even considering it is that I would be living in a car-centered area where I wouldn't have to spend more than a couple of minutes a day outdoors during the summer. Compare that to NYC where I used to live: milder summers, but still hot, and I had no choice but to endure them (and winters, and rainy days) because I couldn't drive to most places I went to. The unpleasantness of that far outweighs all the advantages of walkable neighborhoods for me.