Some [just some] of the numbers on autosprawl subsidy - from Grist and Litman

Local roads, where you most likely do the bulk of your daily bicycling, are a different story. The cost of building, maintaining, and managing traffic on these local roads adds up to about 6 cents per mile for each motor vehicle. The cost contributed to these roads by the drivers of these motor vehicles through direct user fees? 0.7 cents per mile. The rest comes out of the general tax fund.

This means that anyone who owns a home, rents, purchases taxable goods, collects taxable income, or runs a business also pays for the roads. If you don't drive a car, even for some trips, you are subsidizing those who do -- by a lot. The best primer on this is economist Todd Litman's highly readable 2004 report "Whose Roads." (It's also the source for most of the figures in this column. Download the PDF here). A journalist recently crunched the numbers in Seattle and found the discrepancy in 2010 to be as wide as ever.

Grist