I have been struck lately by how much space privately-owned automobiles take up. It’s the Starbucks on Marshall that got me thinking about it, and just the sheer percentage of that lot that is devoted to moving and storing cars.
All space devoted to use for cars is people-unfriendly. Car space increases distances between destinations. Traversing car-prioritized spaces outside of a car is universally unpleasant—you’re in a place where you’re not at leisure and your movements are often controlled by regulation or threat of immediate physical force. Wherever cars are at rest or in motion, it requires space that a human outside of a car can’t occupy, and even more space that is unpleasant or dangerous to occupy.
This post is going to have a lot of rough calculations that can be quibbled with, refined, and extrapolated with better information, but let’s just explore how much space we’re dealing with, and what dedicating all that space to cars does to a city.
The Average Space Consumption of One Car
An average car, parked by a non-professional in ordinary use, occupies about 170 square feet when it is sitting still. However, without perfectly efficient turnover, each car needs more than 1 parking space: one where it is sitting now, and one waiting for it wherever it will arrive. When a car isn’t sitting still, it needs the space it occupies, as well as some multiple of that in front of it—a multiplier that grows depending on how fast it is going. One car going 30 mph needs about 75 feet to stop—an additional 750 square feet! A faster moving car needs more space. So, at all times, whether sitting still or in motion, a privately-owned car requires more than the 170 square feet it currently occupies. And an autonomous car wouldn’t be an exception to this math.
As a result, cars consume an enormous amount of urban space. This tool lets you investigate how much public right-of-way is dedicated to certain modes of transport in certain cities. Minneapolis isn’t included, but one might consider Portland a close substitute. The tool reveals that about 80% of Portland’s travel lane miles are designed for cars (27 million+ square meters), and that Portland dedicates 3.2 million square meters of land to parking lots (this doesn’t appear to include street parking!)
Minneapolis(, A) Land Devoted to Cars and Car Storage
This is a map of Minneapolis’s metered street parking. (source) A tiny fraction of street parking costs are recovered with user fees—most street parking is paid for by city residents whether they own a car or not. And the city has dedicated a lot of space for that purpose. What percentage of Minneapolis city street miles can we assume offer “free” (subsidized) parking? Let’s go with what I think is a conservative number: 50%.
Minneapolis has 1,040 miles of streets. (source) Assuming parking is allowed on both sides of 50% of those miles, and you’ve carved out 54,912,000 square feet of public property (1,260 acres) for the exclusive use of private car storage. (Compare this estimate to the estimate in this article that Seattle dedicates 5% of its land to on-street parking, and it suggests the estimate might be low; 1,260 acres is just 3.6% of Minneapolis’s land area.) That’s parking for about 323,000 cars.
The adult population of Minneapolis is about 337,000. Every adult in Minneapolis has roughly one free on-street parking space available to them, whether they own a car or not. That’s an enormous subsidy for car ownership, and incentive to own a car. And that’s before accounting for a single off-street parking space. I’d love it if someone figured out exactly what percentage of city-owned property this is—that’s the percentage of city property that literally is a giveaway to car owners.
Yet there’s also vast space within the city privately devoted to parking. Let’s just talk about the 150,000+ parcels with garages in Minneapolis. (source) I’m not familiar with a good source of information that identifies how many of those are multi-car garages, but I bet one exists. For now, let’s assume half of the garages are 2-car, and the rest are 1-car. That’s an additional 225,000 parking spaces, or 38,250,000 square feet. Bringing the % of Minneapolis land area devoted to car storage up to 93,162,000 square feet, 6.1%, without counting a single square foot of driveway, parking pad, carport, surface lot, parking ramp, or other use designated for or suited for private parking. Nor any of the space committed to travel lanes.
The Land-Use Opportunity Costs of Parking in a Car-Dependent City
With all that established, let’s talk about just the opportunity cost of all that car storage.
Every square foot of land devoted to parking could be used for something else. The land in the public right of way that is devoted to parking could be used for other, more sustainable modes of transportation, or for simply having narrower (safer, calmer, more human-friendly) streets, greatly reducing the cost to maintain those streets and creating more space for recreation and for just being a person outside of a car.
And private land could be used, instead, to house people. A landowner could replace a two-car garage with an ADU—and use that land to generate income and provide much-needed new housing units rather than store a depreciating, costly personal asset. Or, that space could be used to provide services people need (e.g., childcare, a neighborhood grocery) closer to where people live, so they don’t feel compelled to drive somewhere else for them. Or, just for quiet enjoyment, not in a car.
The fact that these shifts aren’t happening, and face considerable opposition whenever they are attempted, despite how desirable they are, tells me that we need to change the incentives for the choices people are making. We need to create a city where people don’t feel like they “need” a car. To do that, we need to recognize—and commit to changing—just how much space around us is allocated in a way that promotes car dependency. That commitment of space simultaneously undermines and discourages a more connected, healthy, human-friendly, and less car-dependent urban environment.
So many costs of car ownership are hidden, or “built in” to things, and therefore not recognized. That leads people to disregarding real costs when evaluating transportation-related decisions. This includes the very space the cars take up—space consumption that itself contributes to the “need” for cars.
We need to invest in alternatives to car ownership, and also to stop quietly subsidizing car storage and other car infrastructure so we can take cities back for people. These land-use choices need to be quantified and appropriately priced/taxed so we can start making smart decisions about whether or not this is the best way to use the space around us. To start moving the needle, we must use both the carrot and the stick.
(I also want to link to this post that explores these ideas in more mathematical detail, which Bill Lindeke just linked to in his post on parking permits in St. Paul. The author estimates fewer on-street spaces than I did, due to different assumptions about parking-spaces/mile. Less important than whether a blogger comes up with the right number is that the city take a full inventory, and then use that data to guide transportation and land-use decisions with its goals in mind).