Mark me down for all of the above. While I could theoretically drive my car to work, cycle commuting is more of an alternative to taking metro than an alternative to driving for me. Note that bike commute is actually a faster way to cover the seven miles between home and office than the train (30-40 min. vs. 1 hour by the time you throw in walking to and from metro stations). So, in addition to all of the above, mark me down (perhaps oddly and unexpectedly enough) for time savings!!! :-)