Three spaces per car…

I attended Peter Guest's presentation at Oxford University yesterday. Peter is a parking consultant, former president of the British Parking Association, and PT's all knowledgeable correspondent in Europe and the Middle East.

He spoke to a group of transportation planners from the university. He was invited because the group felt it knew a lot about transportation, but very little about parking. I would suggest that many of the transportation decisions made would bear out the truth of that statement.

While I agreed with most of the overview on parking that Peter gave, I question one reference. That is that each car needs three parking spaces – Home, Work, and Play (or shopping, etc). That statement troubles me a bit.

First of all, many people own cars but use public transportation to go to work, or car pool. That being the case, those people only need two spaces, home and play.

Second, when we go to play, we often go with another couple, therefore removing one car from the play scenario.

Third there are always some cars on the move – except for maybe 2-4 AM. This means that except for home, many cars are 'in between' at some point and if you are ever on the Santa Monica Freeway, you know that it's not just a "few", but a ton. That also applies to London's famous "ring road", the M 25.

Fourth – although this may not "count" many cars are parked in places that aren't formal parking spaces (open fields, vacant lots, front lawns, and parked illegally on streets.)

Fifth, most parking lots are empty most of the time. And even at peek hours, are seldom full.

I don't want to do the 'numbers' since I have no studies (Peter's main point in his presentation, that frankly there are few learned studies that focus on parking) to back them up. However I think that logic would, considering the five points above, lower the number of spaces per car to at least two, and in fact, probably under two a bit.

So, if planners plan for three spaces per car, they would over plan by at least a third.

What I'm saying is that if we simply use our God given minds and add a bit of logic, some 'facts' we take for granted fall away as urban legends and can be seen, on their face, as simply not "spot on" as they say here.

JVH

Comments

[Peter Guest]

Glad taht you were paying attention! I believe that the figure of 3+ spaces per car came from Doctor Phil Goodwin who is one of the most highly respected transport planners in the UK (Shoup x 2) but I agree that it is a bit of a guess. I fully agree the points you make but office and home spaces are often empty when not used and of course the third "play" space is represented by all those public spaces which are seldom 100% used, so this adds to the figure. The estimate of parked 95% of the time is reasonably robust average distance travelled a year, average speed and you have the time a car is moving. the rest of the time it is parked and in the UK thats 95%.
lets agree that the figure is the right ballpark but not precise.

Peter Guest

[Don Shoup]

John and Peter,

Bryan Pijanowski at Purdue University used high-resolution aerial photography to estimate the aerial footprint of paved parking lots in one Midwestern County. He found three parking spaces per resident driver in urban areas. This estimate excludes all on-street parking spaces, all residential parking spaces not in paved lots, and all structured parking. Here is the link to a short description of his study.

http://www.purdue.edu/uns/x/2007b/070911PijanowskiParking.html

Here are a couple of other links to the topic:

http://www.salon.com/news/feature/2007/10/01/parking/

http://web.ics.purdue.edu/~bpijanow/research.htm

Don Shoup

[SN]

"Fifth, most parking lots are empty most of the time. And even at peek hours, are seldom full."

Er. when the space is not filled it is still a "parking space" and thus it is not being used in some other capacity. The private automobile is simply an enormous waste of resources (energy, time and space).