While I somewhat understand the logic in this I find it an interesting mindset and somewhat illuminating insofar as how attached we are to the automobile. That the owning of an automobile has become such a necessity that we discount those costs as if they are simply a given. Kind of like, "I have to breathe don't I?"

I suppose in trying to come up with a formula to determine "at what point does commuting save $$" a few things are revealed:

#1- If you are attached to owning a car and simply must have a car to the point where you don't even factor in the cost of the automobile and it's upkeep as part of the equation then you will indeed "save" less money commuting on a bike.

#2- If you must have the latest bling for your bike, factor in all your recreational bike bling, must have the latest, the newest and the best for your bike. And you have all your repairs done at a bike shop. You will save less money commuting by bike.

#3- If you give up your car(s) entirely, if you go car-lite (ie. a two car family becomes a one car family) or you're a pragmatic realist in your accounting and factor in the cost of owning the automobile including initial costs, insurance, all upkeep and things like parking, tolls, parking tickets, fines registration etc. then the bicycle will definitely win out on the balance sheet. And, if 5,000 miles a year on your bike means 5,000 less per year on your car it could mean an extra year or two of ownership of the car reducing the initial cost over time. In other words, delay the purchase of a new car or increase it's resale value. But, overall, car ownership reduces the savings.