Coincidentally, a high number of these weak social ties* is one of the best predictors of life satisfaction and good mental health. In contrast, there's a strong correlation between longer car commutes and less life satisfaction and poorer mental health.

Huh, I knew both of these facts independently, and somehow never put them together side-by-side like this before.

* People that you see and lightly interact with regularly, though you don't know them. Like the guy you see on the tram every day, for example.