My exwife was a CPA, and I'm sure she could give you the $/mile figures but I've never had the desire to figure things out too closely. I have decided to keep closer track the changes in my health, and adding in those benefits would definitely make commuting more economical. One other conclusion that could be drawn from your detailed figures Andy is that you clearly need to ride some of your bikes more. Shouldn't you turn the computer off and go out and ride?
