Walking versus Public Transit

Today I am lucky enough to live within a 35 minute walk of my office. But, because I live in Boston, and I would prefer not to be sick 6 months out of the year, I typically take the bus at least when it's below 50 degrees or rainy. I have a love/hate relationship with the bus. I love that it continues to expose me to the GP (general public). I hear the latest tunes out of other people's iPod's, and I know all about my neighbor's son's hockey tournament this next weekend. I hate the bus because- like all forms of transportation, other than our feet, it is polluting the environment. But, my justification for riding the bus is that it would be going with or without me. It doesn't matter if I am on it or not. At least I am not driving into the office. I might as well enjoy the comforts of the bus, relish in the goings on of my neighbors, etc... But, on day's like today- when it's above 50 degrees and sunny to boot, you will see me on foot, sparing the air and listening to the sounds of birds and passing cars...