@OP

You're right, bike commuting is a *lot* more expensive than walking. My good walking shoes (2 pair, $180) are new this year and show no meaningful wear yet. The bag I use for most walking trips was a freebie.

By comparison, my bike was $800, is a year old, and has needed no maintenance. That's a lot more expensive! I guess I might want to adjust the brakes this fall, but that's about it.

Oh... wait... you were talking about cars. Don't use those.