OK, i have only skimmed this book, but it is like THE most acclaimed car/culture/environment book b/c of it's age - written sometime in the 70s i think... and i know a fair amount about this subject from various other sources, so since the comments here seem to present the general dominant US view, i'll try and widen the viewscope a little bit here...

about the numbers and statistics: if i remember right these are estimates of the TOTAL costs and sizes. For instance, $6000 (i think AAA's current number is like $6500 per year) is about the cost TO THE USER to own, insure, maintain and operate a vehicle... $6000 isn't too bad. But there are so many other costs like road construction, police service, oil subsidies to keep prices low and stable, military expenditures to help denfend/protect our oil source interests, pollution costs, etc... these costs are not visible in the $6000/year but *someone* is paying for them - in the US it gets taken out of tax dollars that could go for education or other social services --- how much money does your state or community spend on new road construction? how much money goes to police service to give speeding tickets? how much for the fancy traffic monitoring systems (signs, video, real-time monitoring) in most major cities to help alleviate traffic problems?

as for the parking space numbers: the 3 is figured as such:: 1) most people have their own parking space at home (or on the street in front of their house) that is almost always not used by them when they're not home. 2) most people have a parking space at work - while it may not be dedicated, your company must have enough spots for all the workers who drive -- and if you visit a company parking lot at 3am, you'll see almost all spots unused.. 3) then when you shop you need a parking spot - again you don't have a personally reserved spot, but every place you shop needs to have enough extra spaces so there's one for you whenever you want to shop there, so they need to come close to meeting MAXIMUM capacity ---- admittedly there is some overlap - some people live in urban areas where others park for work when they're not home but most people live in the suburbs and no one parks in front of their house during the day. and yes, there is sharing between different retail businesses... but again, if a store doesn't have enough parking then people will shop somewhere else where they can find parking (or maybe free parking) ---- thus, the statistics are difficult, but it's very close to 3 parking spots for each car operated. think about the Walmart parking lot and then the Safeway parking lot and then Blockbuster, etc... and then all the parking garages and parking lots at your company...there's a lot of parking out there and most of the stops are empty at least half the day and often 90% of the time (think about the last spot at your company or the last row at the Walmart - is it ever full? if so they're probably planning to build more right now)

in the US, the car is the accepted standard and these service expenditures go unnoticed. as an aside, in political terms, money spent on road improvements or infrastructure is always considered an 'investment' -- like "we need to build this road to invest in our local community", but when rail projects come up people say 'the train service is not profitable. Amtrak's been losing money for years. Why do we we need to SUBSUDIZE trains?'... no one expects for money spent on roads to turn a profit (possibly some toll roads but i think most loose more money than they earn), but for the train it is not an 'investment' but a 'subsidy'... do your tax dollars spent for road construction ever turn a profit? this represents the American mindset with the car as the standard.

besides the hidden societal costs of operating a motor vehicle, another big item that would help reduce people's often excessive car use is reducing the fixed cots to be per-mile costs so people realize the real costs of their actions... for example, with a few exceptions for discounts if you work near home, once you fork over the cash to insure you car it costs you no more to drive 100,000 miles in a year than 10 miles... and most people don't make the connection between usage and maintenance - they just fix the car whenever it breaks... so the per-mile cost of using a car looks like just the cost of gas (US price of gas also reduced through lots of government expenditure for oil subsidies and military protection - your gas taxes and auto registration do NOT cover all of this) which is quite cheap... i.e. if work is 5 miles away and gas costs $1/gal and your car gets 30mpg, then it *seems* like it only costs $.32 to drive to work and back... but this is not counting what you already spent on insurance, what you will spend in maintenance, and all the external costs already paid by society for roads and oil, plus the costs from pollution that society will bear in the future... even just your real direct personal *usage* cost is much higher than what you think(what's the current IRS number $1.25/mile?? i haven't driven for business in the US in a while)... not to mention the *real* total cost of driving...

in most of Europe gas costs 2-3 times as much as in the US so the per-use costs are higher, but in general the major result is that people buy more fuel-efficient vehicles and other transportation like public transit becomes more attractive because of increased money savings... but even in Europe with higher registration taxes and gas prices most of the costs are still 'invisible' to the user... the system is still set up to encorage people to drive as much as possible by making it cheap and easy.

and the main reasons why so much US government tax money is spent on the car infrastruture have to do with the fact that the automobile industry has a lot of money and makes more money the more we drive... and now almost all of business especially in the US is 'dependent' on cars (for workers to get there and shoppers to come buy stuff) so it's an 'investment' in society to makes car use cheaper, easier and more stable... i, of course, don't necessarily agree