"The total subsidy for parking is staggering, about the size of the Medicare or national defense budgets. But free parking has other costs: It distorts transportation choices, warps urban form, and degrades the environment."
It's the same distortion you have when politicians whine about "subsidies" for Amtrak or other rail service, yet they don't think twice about how taxpayers are ponying up for everything from fixing potholes to paying billions for the Big Dig so people can keep driving in their private automobiles.
Another problem pointed out in the book, according to USA Today: "Cities and suburbs require too many parking spaces around malls, apartments and office buildings. That wastes land that could be put to better use, and for much of the year, hundreds of spaces sit vacant."
Update: New Urban News has a great article about Donald Shoup's book on parking, highlighting a very important point -- too much parking can be as damaging to a business district as too little. Sound crazy? Excessive parking "reduce[s] compactness and proximity — chief advantages of an urban location," the article notes.
Formulas for off-street parking actually hurt residents of affordable housing who don't have private cars, because they're forced to pay for its availability anyway. "Nonprofit developers in San Francisco have estimated that parking requirements add 20 percent to the cost of each affordable housing unit and reduce the number of units that can be built on a site. ... A study in Oakland, California, found that requiring one parking space per dwelling 'increased housing costs by 18 percent and reduced density by 30 percent.' "
Such requirements also make it impossible to continue building in traditional styles of higerh density, popular older residential and commercial areas.
And, Shoup notes, many of the requirements for a set number of parking per store or residence appear to be randomly generated.
“A gas station must provide 1.5 parking spaces per fuel nozzle, and a mausoleum must provide parking spaces per maximum number of interments in a one-hour period. Why?” he asks. “Nobody knows.”