However, one of the largest costs of auto-dependency is hidden in plain sight: the cost of providing parking spaces. The financial cost of providing parking spaces can be staggering. According to Todd Litman, “most communities have three to six parking spaces per vehicle (one a home, one at the worksite, plus spaces at various destinations such as stores, schools and parks)”. As car parks occupy around 30 m2 apiece, this means 90-180 m2 per car.
In Auckland, where suburban land prices range from around $250/m2 (west and south Auckland) to over $1000/m2 (inner isthmus, lower North Shore), surface parking would cost $22-90,000 per car. That’s more expensive than the cars that occupy those spaces!
Moreover, land that is devoted solely to cars cannot be put to higher and better uses, such as dwellings, businesses, or public spaces. In a successful city, we would expect the value of those other uses to continue rising, meaning that the opportunity cost of car parking will also rise. Space is expensive in cities, and parking is an inherently inefficient use of land.
This spatial inefficiency is exacerbated by the fact that many cities have ended up with more car parking than is necessary. Eric Jaffe in Citylab reports on some important new research on parking oversupply in US cities:
Some new research reminds us just how oversupplied parking really tends to be in American metro areas: in a word, enormously. Rachel Weinberger and Joshua Karlin-Resnick of Nelson\Nygaard Consulting Associates analyzed parking studies of 27 mixed-use districts across the United States and found “parking was universally oversupplied, in many cases quite significantly.” On average across the cases, parking supply exceeded demand by 65 percent.
The researchers focused on districts with both residential and retail developments in a variety of settings—17 suburbs, 6 cities, and 4 towns—mostly in New England or California. (Interestingly, a third of the areas were documented as having the impression that local parking was scarce.) By looking at previous parking studies in these areas, as well as satellite imagery via Google Earth, they identified existing parking supplies and peak weekday and weekend demands.
Critically, the researchers also took into account the accepted practice of supplying 15 percent more spaces than necessary—a sort of buffer zone that reduces the congestion caused by drivers circling for spaces.
In all 27 districts, spanning places with 420 spaces to those with 6,600 spaces, Weinberger and Karlin-Resnick found an oversupply of parking over and above the buffer zone. The oversupply ranged from 6 percent up to 253 percent across the study areas (below, the highest over-suppliers). And in the nine areas that had believed parking to be scarce, the oversupply ranged from 6 percent to 82 percent.
These are pretty extraordinary findings. An average oversupply of 65% means that two out of every five parking spaces are, essentially, useless. We would never tolerate such waste in any other part of our economy – if, for example, two out of every five meatworks were sitting idle, we would start shutting down the unprofitable ones.
I highly recommend reading the rest of the article, as there are a number of other interesting findings in the research. One in particular stood out:
Interestingly, a third of the areas were documented as having the impression that local parking was scarce.
The researchers found that this was not correct – parking was in fact oversupplied in each one of these areas. Policymakers and businesses in these areas significantly overestimated the amount of parking that was truly required. It’s common to hear retailers complaining about the loss of on-street parking for cycle lanes and bus lanes, but the evidence suggests that we should treat their claims with caution.
The same thought occurred to me when reading the recent Motu paper on the cost of planning regulations. Based on a survey of 16 Auckland-based developers, the authors concluded that:
There were diverse views of the impact of car parking requirements on developments, reflecting differing development types. CBD apartment developers, particularly those developing at the affordable end of the market, prefer to include fewer car parks. They saw car parks as a cost to the development as the market value of a park was less than the cost of including them on the development. In contrast to CBD apartment developers’ views, suburban apartment developers tended to favour offering more car parks.
However, some of the comments from developers made me wonder whether they had also fallen into the trap of overestimating parking requirements:
“The optimal number of car parks in a suburban apartment development targeting the mid to upper end of the market is 2 to 3 per unit with additional common parking for guests”
Now, I haven’t been keeping a close eye on suburban apartment developments, but I’d be extremely surprised if developers were actually building three car parks per unit. If anything, the trend seems to be for fewer car parks. For example, the Merchant Quarter apartments in New Lynn have unbundled parking, while the apartments planned for Alexandra Park will have only one car park apiece.
Do you think Auckland has a parking oversupply? If so, what should we do about it?