Thanks everyone!

My commute length is pretty flexible because I have a folding bike and can bike part way and take the bus or the T part way (I live too far out to bike all the way except maybe on bike to work day )... the most I'd be biking is 7-8 miles one way (home to T, T to work), or double that if I did the round trip. So far I've only done one way because it seems like mornings are still way cold here.