The cost of bicycling

Metropolis Magazine.jpg
Originally uploaded by rllayman

This photo ran in Metropolis a couple years ago. Here's the caption:

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Kimberly Viviano, Viviano + Company, Oak Park, Illinois

The Big Idea A system of signs posted along Chicago's lakefront would inform drivers and bicyclists of the human, financial, and environmental benefits of riding a bike to work versus driving a car.
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I don't see how the numbers are right though, unless the cost of bicycling is somehow balanced off by monetizing health benefits.

If I can manage to keep a bike for 18 to 36 months, excluding maintenance costs, the hard cost of buying the bike, if I get one of the end of the year clearance bicycles at Bike the Sites, is about $160 to $200. So the cost per day is less than 30 cents. But that still adds up to far more than $38.80/year. But it's a lot less, even with one annual tuneup and tire upgrades to kevlar to reduce flats, than one month's car payment.