Hmm, my own parking lot post had $100/month for ground parking spaces, in Cambridge with high values. I also guess $6000-$60,000 in value per land. Of course a car needs multiple parking spaces to be able to go places, so the value per car could add up, but he's saying per space. Let's see! It'll be a short chapter, anyway

Ooh, a finesse! Consider a UCLA lot that had 200 spaces, and is replaced by a structure with 750 spaces. The structure is *adding* only 550 spaces, and we can divide the structure cost by that to get get a marginal cost of parking spaces, while dodging the question of highly variable land value. In this case the construction cost was $12.8 million, or $23,200 per space. He also notes that a garage is built when land is too valuable to be used for simple lots, so this is a lower bound on the cost.

Looking over 15 UCLA structures, he gets a 1961-2002 average cost of $22,500 in 2002 dollars. For 1977-2002, $27,800. This includes some underground garages which are assumed to not displace any lot spaces but cost more, over $30,000 per space. Older aboveground spaces were cheaper, average of $14,500, (low $11,600, high $17,000) Big jump between 1969 and 1977; I posit either having to accommodate bigger vehicles or tougher earthquake codes.

My posit is wrong! He says the later structures are smaller, so the fixed costs of ramps, elevators, and stairwells are spread over fewer spaces. Hmm, but one of the most expensive structures is an aboveground from 1990, and it's the biggest one on the list. 2505 spaces added, at $28,900 each. Perhaps I should write him about that.

Land costs figure indirectly, driving the later need to build underground, or to use smaller free lots.

Richard Willlson found that land+construction cost for structures was $14,700 per space in 1995, for SoCal suburban office developments, matching the older UCLA numbers. So that's a lower bound... plus the opportunity cost of having to look like suburban southern California.

He gives more data to show that these are reasonable numbers. Some cities let you pay a fee in lieu of providing your own spaces, and unlike parking requirements these numbers are based on research. Lake Forest charges $18,000 per space, Palo Alto $51,000! These costs probably *do* include the land costs. Seattle paid $61,000 for a space underneath a shopping center. Some underground garages in Japan cost $280,000-$414,000 per space! combination of having to be built in front of a railway station and not disrupting traffic, and earthquake codes, or in one case, being built under a river.

So $22,500 is a good deal.

At 4% interest amortized over 40 years, capital cost would come out to $94/month. But parking structures also have maintenance cost; all those vehicles take a toll, there's weather damage, and such. UCLA -- which has nice weather -- spends $33/month per space on admin, lighting, cleaning, insurance, etc. Voila, $127/month. And he gives various reasons for this being low (including UCLA not paying property taxes, 4% being low normally, and 40 years being a long time.) An actual recent structure costs $31,500 per space (underground), and the debt is 27 years at 6.125%, for $201/month. The 6% is low too, for UCLA itself, and in general: tax-exempt interest, and backed by the revenues of the whole parking system not that particular structure, so the risk is insured.

Average price of commercial parking in downtown Seattle is $200/month. (A neighbor I met tonight said he pays $125/month for a space in the apartment lot.) In Bellevue, $138. Across 43 downtowns, $141. An estimate for Ann Arbor was $160.

If land is $30/sqft then a parking lot space of 330 sqft costs at least $9900 by simple multiplication. Ann Smith says $12,000 but he gives no details. Maybe interest and operating costs.

And then there's the cost per *occupied* space, since many garages are rarely if ever at full capacity...

***

And that was just the cost of providing the space. Then there's the knock-on effects of enabling more travel (higher supply reduces the money price of parking) on congestion and pollution. A UCLA Environmental Impact Report provides data, with estimated car trips and miles per trip. Estimates for congestion cost in LA range from 10 to 37 cents per vehicle mile traveled. 15 cents is a modal estimate for a toll to raise rush hour freeway speeds to 35-40 mph. Using only 10 cents gives a congestion cost of $73/month per UCLA space. Emissions costs are estimated at 6 cents a mile, or $44/month. A New Jersey study estimated 8-13 cents/mile. CO2 isn't included in the emissions price. The trip length estimate is 8.8 miles vs. a SoCal average of 15.

So we have a very conservative congestion+pollution cost of $117/month per space.

Also not included: noise, accident risk from driving, ecological cost of impermeable parking lots (not sure that's fair, if the alternative is urban buildings) and of oil drip runoff.

UCLA's spending $201/month-space for that new building. We add in $117 for $318 total. A parking permit to use the space only cost $54, not even covering the explicit financial costs. He quote a student who was induced by the low cost to switch from a vanpool to solo driving.

***

EDIT: I didn't think to think about the total cost. Something like 160 million cars in the US. At $20,000 per space, that's 2e4*1.6e8 = $3.2e12 = $3 trillion in parking space wealth. Except you need 2-4 spaces per vehicle to be useful, so $6-12 trillion. At $200/month per space, $60-120 billion/month, or $720 billion to $1.4 trillion/year.

See the DW comments at http://mindstalk.dreamwidth.org/354