Parking 🅿️ Where do parking minimums originate?

[P_Johnson76]

Here is a Subway with 53 parking stalls plus a drive through lane.

Where did parking minimums come from? How were they determined? In all seriousness, what math was done to suggest a low-priced sandwich shop needed that much parking?

And as planners, what are we doing RIGHT NOW to make sure we're not complicit in expanding this type of land use?

 

[Dan]

Here is a Subway with 53 parking stalls plus a drive through lane.

Where did parking minimums come from? How were they determined? In all seriousness, what math was done to suggest a low-priced sandwich shop needed that much parking?

How dare you question the wisdom of the planning ancients! Next, you'll want to know the origins of the 35' building height limit that practically every North American zoning code sets for low intensity residential and commercial zones. (One day, when I was bored, I traced the origins of 35' height limits back to British building laws from the early 1800s. More on that in a future post.)

Anyhow, outrageous parking requirements. When car ownership started to become more widespread in the 1920s, traffic engineers often recommended the elimination of all off-street parking as a way to relieve congestion. Those cars that would normally be parked curbside had to go somewhere, though.


Saaaay there ...

Provision of off-street parking was a hot issue among planners through the 1940s and early 1950s, as car ownership exploded. Early on, vehicle parking was seen as a problem that government would solve, by building municipal parking lots and garages. In the 1940s, zoning code requirements for off-street parking started to get a lot of attention in planning and civic management periodicals, in the context of being something novel and innovative.

ASPO Newsletter (the predecessor of Planning magazine), December 1941

ASPO Newsletter, August 1948

ASPO Newsletter, September 1948

ASPO Newsletter, April 1952

ASPO Newsletter, February 1954

Roads and Streets, June 1949

Zoning Applied to Parking, a report by the Eno Foundation for Traffic Control from 1947, is one of the earliest studies that examines and compares some of these early zoning requirements for off-street parking. Like the building and fire codes of the 1800s that required all brick construction or thicker walls for buildings over 35' tall, the report might offer some clues about the origins of commonly repeated parking requirements for certain uses.

 

[UrbanUnPlanner]

Next, you'll want to know the origins of the 35' building height limit that practically every North American zoning code sets for low intensity residential and commercial zones. (One day, when I was bored, I traced the origins of 35' height limits back to British building laws from the early 1800s. More on that in a future post.)

You'll want a height limit somewhere in that neck of the woods for your low-density zones anyway to avoid needing to drag the 26' minimum clearwidth required for aerial apparatus deep into your residential neighborhoods, unless your fire chief can operate their ladders on narrower roads of course.

Back to parking, though. As a rule of thumb, most parking minimums are arse-pulls or copy-pasta jobs; the closest to scientific numbers that you'll find are based on trip generation manuals (the ITE publishes one) or site-specific trip generation studies, but those generally don't account for the modal share at any given location: if a site generates 10,000 trips per day but 75% of them can be picked up by a nearby subway station and 20% of them can be made using active transportation alone, then you only need to provision parking for 500 auto trips/day, not 10,000, no?

 

[luckless pedestrian]

All hail ITE!

 

[mendelman]

Back to parking, though. As a rule of thumb, most parking minimums are arse-pulls or copy-pasta jobs;

This has been my experience, effectively, 100%.

All the parking mins in all the munis I've worked for so far (all small to medium sized suburban/small city munis) were clear copy-pasta jobs and were wildly out of scale with actual functional reality.

Thankfully, many munis are starting to realize it's not some new phenomenon of human settlement anymore and we spent 2-2.5 generations building this way and the evidence is clear in the existing 60+ years of built environment out there.

There is too much parking built and it's a functional and psychological burden on us now...mainly because many believe it's some kind of law of nature and a first order problem. When it's not a law of nature (aka 100% human construct) and designing sites for cars first then the humans is objectively harmful.