In the book, I write quite a bit about the true costs of owning and operating a car, and offer tools and tips for figuring out just how much money you may be spending on your big metal dependent every year. But there’s a whole other side to this that I barely touch on in the book: what driving a car costs everyone else in what economists call “externalities.” For example, how much time do other drivers lose collectively by the addition of one more car into traffic, and what is the collective value of that time?
As you might imagine, this is a pretty complicated question to answer, but recently Charles Komanoff, a transit policy analyst based in New York, unveiled his analysis of what each car added to Manhattan traffic costs in externalities. His finding? About $160 per car per day.
Felix Salmon has a relatively easy-to-understand write up of this analysis based on his discussions with Komaroff, and of course, Yglesias weighs in too. I imagine Komanoff’s spreadsheet (.xls) is a bit too complicated for me to fully digest, but I’m going to take a look to see if I can get a sense of how difficult it would be to adapt his analysis to another city like Chicago.
