I'm speaking here for myself, not my wife. I bicycle 95% of the time, but sometimes the weather is just too severe, and there's no transit for the 8-mile trip to work.

This week, I'm on business in St. Louis. I have a (newly purchased used) folding bicycle with me. I'm now combo riding the bike / taking the Metrolink / taking the bus. I could definitely go car-free with this setup.