Here is an excellent reason for why you may want to spend more time walking:
People have noted that walking seems to have a special relation to creativity. The philosopher Friedrich Nietzsche (1889) wrote, “All truly great thoughts are conceived by walking” (Aphorism 34). The current research puts such observations on solid footing. Four studies demonstrate that walking increases creative ideation. The effect is not simply due to the increased perceptual stimulation of moving through an environment, but rather it is due to walking. Whether one is outdoors or on a treadmill, walking improves the generation of novel yet appropriate ideas, and the effect even extends to when people sit down to do their creative work shortly after.
The results were a bit inconclusive as to whether outdoor walking is better than other forms of walking, so for now we will just say that walking -- in general -- is good for creative thinking. But where my mind immediately goes is: Does this finding scale up?
In other words, if you were to take two different cities -- City A where everybody, for the most part drives, and City B where everybody, for the most part, walks -- could you find any evidence that City B was on average more creative than City A?
I guess one way you could measure this is through patents. And if you were to look at patents per capita in the US, you'd likely find cities like Princeton (NJ), Redmond (WA), and cities in Silicon Valley near the top of the list. I'm not sure there's an obvious correlation here.
But it is kind of interesting to think about a possible relationship between urban form and creativity.