A Modern City for People Would Devote Less Space to Cars

Minneapolis Skyline View from 24th Street Pedestrian Bridge

Minneapolis Skyline View from 24th Street Pedestrian Bridge (by Tony Webster under CC-BY-2.0 license)

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

Map depicting a portion of Minneapolis, with metered parking identified

There’s no such thing as free parking

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).

Christa M

About Christa M

Attorney. I do law stuff, ride bikes, and paint murals. Member of Hourcar & Nice Ride, and customer of Freewheel Bike and The Hub Bike Co-op.

62 thoughts on “A Modern City for People Would Devote Less Space to Cars

  1. Melissa WenzelMelissa Wenzel

    Look at any establishment that has parking. Then compare the footprint dedicated to parking versus the actual establishment. The first time I did this was 2 years ago at a Target in Blaine. I estimated less than an acre for the store, and ~3 acres of parking. When I went, about 5% of the parking lot was filled (8pm on a summer weekday). It was rare for me to drive to a Target; I normally bike to the one I live near but was visiting family and needed a quick stop. I don’t think I’ve driven a car solo to Target since.

    1. Jeb RachJeb Rach

      I did a rather quick Paint job trying to see how much space the St. Paul Midway Target parking lot takes up. Based on some quick copy/paste, the parking lot is as big as the Target itself, including some green space on the side and the loading dock.

      Remember, this is a Target that’s half a block from the Green Line and doesn’t share their parking lot with any other stores. Frankly, it’s ridiculous.


      1. Jeb RachJeb Rach

        Speaking of large-lot Targets, the Lake St. Target is just as bad, and that’s along both the Blue Line and the high-frequency portion of the 21.


        There’s probably a lot more, but these are two that stick out specifically since they’re full-size Targets near high-frequency, high-investment transit. (The Red Line doesn’t count. 🙂 )

      2. Andy Wattenhofer

        Builders are typically required by city code to provide a number of parking spaces based on the size of the building, right? Regardless of factors such as proximity to mass transit. This is one thing we could change.

        And that Target lot sits empty over night. Parking lots are built for peak usage even though most of them are underutilized much of the time. It is such a waste!

        [WORDPRESS HASHCASH] The poster sent us ‘0 which is not a hashcash value.

  2. Monte Castleman

    “The fact that these shifts aren’t happening, and face considerable opposition whenever they are attempted, despite how desirable they are”. seems to indicate a substantial portion of Minneapolis residents do not actually share the opinion that they are desirable.

    1. Christa MChris Moseng Post author

      The premise is acknowledged and addressed in basically every subsequent sentence in the post. There is a clear need to evaluate and address the incentives and disincentives that cause people to think they don’t want those things, largely because people feel they “need” a car.

      Opinions and preferences aren’t immutable—not within individuals, and not within populations.

    2. Justin D

      So what? Doesn’t change the fact that they are generally desirable. Walkable, bikable areas are generally pretty valuable, judging by real estate prices. Saying that some people disagree isn’t really saying anything about the desirability of these areas. You can always find some people who dislike something that many people like.

      1. Cameron Slick

        I have nothing but unadulterated condescension for people who struggle to parallel park, and feel otherwise entitled to free, ample parking.

        1. Melissa WenzelMelissa Wenzel

          What does free mean? No cost to you? So someone else is paying for your parking then…

  3. Janne

    Chris, this post reminded me of a CityLab post I saw recently.

    “We may not be able to make health care a right or make housing a right, but the one place the [socialist] revolution has plainly succeeded in usurping the market is in the case of parking.”


    It’s worth reading, especially for the pro-parking among us.

    I’ve been asking people what is more important to us as a community, housing people or housing cars. Every time we dedicate space to a car (and especially when we mandate someone not the driver to pay for that space), we are taking that space away from dedicating that space to a home or a job. As I listen to neighbors and people in public meetings, it sounds like we value sheltering cars over sheltering people.

    1. Christa MChris Moseng Post author

      This is a great post and key to understanding that the status quo distorts people’s preferences. And because each car effectively consumes space it doesn’t even occupy, the effect of that distortion is multiplied.

  4. Carol Becker

    It is a testament to how important mobility is. Driving means having access to hundreds of thousands of jobs, instead of five or ten thousand. Driving is one of the best leading indicators of someone leaving poverty. Driving means having access to good, affordable daycare, instead of wherever you can walk or bike with an infant in the wintertime. Driving literally means being able to live when you are older and it hurts to walk much less try and carry home your food, your new clothes, your cat litter. Driving means getting your kids to school in a city where you most likely are not attending a school within walking or biking distance. And in a city where 20% of the population is kids under 18 and a school system that has chosen integration over the segregation that would occur if all kids just went to the closest school. Driving means being able to take care of your loved ones who do not live near you and seeing friends even if they were not able to live in your neighborhood. Mobility is a huge issue in our society and it is not surprising that there is this much attention given to it. There is no better way to kill a city than throttle its mobility.

    1. Adam MillerAdam Miller

      Driving is definitely the most convenient way to get around in a society that’s structured itself to make that the case. Weirdly, where things aren’t structured that way, people still do all of those things.

      And driving means being sufficiently able-bodied to be able to drive (although, in our society, we don’t really ensure that and have lots of people driving who shouldn’t be, because we shorted the alternatives) and sufficiently affluent to afford it.

    2. Melissa WenzelMelissa Wenzel

      I think I once heard that 95% of NYC residents don’t own a car. I imagine that all ages and abilities live in that city. No car = freedom for many, many, many people. Many industrialized cities have fantastic sustainable transit options and allow people to choose the transit options that work best for them for health, financial, moral, and ethical reasons.

      My preferred transit mode is not something everyone can do (bike year-round for 95+% of my commutes) but I honestly feel more safe on my bike I can see everwhere, no blindspots) and I can read the body language of auto drivers better on a bike than in a car. Plus it helps me exercise regularly. I have an electric-assist bike; I have asthma, arthritis and live a hilly part of St Paul.

    3. Christa MChris Moseng Post author

      The way you write about driving is romantic it almost makes me forget about all the negative externalities it imposes.

      Give people viable alternatives to driving, and they’ll use them, because pretty much everyone agrees driving in a city sucks, they’re just willing to overlook how much it sucks because they feel it is necessary. Everything you list can be accomplished with buses, trains, infrequent car sharing/rental, and proximity. The focus should be on fortifying those alternatives, not rewarding people for spurning them.

      It’s time to look forward toward a future that isn’t hamstrung by land use choices designed around our mid 19th century love affair with the private automobile. Nostalgia for car dependency culture is a luxury we can no longer afford.

      1. Carol Becker

        I think that there are good reasons why the vast majority of people drive. We can romanticize about what the world could be like if we were not stuck with Minneapolis but this is what we have to work with.

        I would challenge your statement “everything I listed can be done with walking, biking, infrequent car use and proximity.” My life simply could not be done with those things. And no amount of “fortifying” would change that. Take my daughter. She goes to school in Bloomington. I can’t drop her off before 8:20 and no later than 8:40. I have to be at work in downtown St Paul by 9:00 am. How would that work without a car? She is picked up either by one set of grandparents, who live in Richfield and take her to have dinner with them or one in Mendota Heights where she has dinner with them? I then have to pick her up and often take her to soccer practice, which thankfully is now in the neighborhood but used to be at Pearl Park or at the fields south of the City. Her last tournament was in Hastings. Before that, it was in North Branch. My partner works along University. In theory she could take the bus but it would probably take a good hour. She comes home to let out the dog at noon, which would probably take a good hour instead of the 10 minutes it takes with a car. I often have a second job at the U or at Hamline University, which I need to leave my regular job and get to by 5:30 and then get home sometime after 9:30. Also understand I have a bad knee and arthritis and often limp, making long distance walking literally an exercise in how much pain I want to endure. Nor do I have time to spend hours travelling as I have an eight hour a day job, a second job and a child that literally cries when I am away. None of this works in the world that you are conceiving of.

        Also, I am a woman and cannot just show up dirty, wet, smelly and disheveled at work or at other events, not like a man can.

        I say this and I am just dismissed by many advocates, as if I shouldn’t exist or maybe they can just drive me out of my own city by making my life harder and harder. With no admission of the impacts of making someone’s life harder. No admission of the impacts of being able to earn a living or take care of a child or take care of an elderly person or even just see their friends.

        I also accept that the Metropolitan Council’s long-range plan envisions no expansion of the base bus system as any new money has to go to fund Metro Mobility. No expansion, just reconfiguration of what currently exists. And maybe an LRT or two to take suburbanites to downtown. So presuming that there will be any transit expansion is simply wishful thinking. The Republicans tried to cut transit funding by 40%

        So we can all dream. But without thinking hard and seriously about how people actually live their lives, it is just smoke. Think about how a parent can live in this city. Think about how someone who cannot just walk or bike can live in this city. Think about how women can live in this city. Then we start to have real dreams that can move towards reality.

        1. Adam MillerAdam Miller

          There are good reasons most people drive: it’s highly subsidized and we’ve made all the other options hard to do.

          As for as to whether it’s the vast majority, I was looking at the city’s profile on MNCompass the other day and noted the 17.6% of Minneapolis household have no vehicle and 30% of the city gets to work other than in a car (transit, bike, walked or works from home): https://www.mncompass.org/profiles/city/minneapolis

          People respond to incentives. The existing set of incentives makes driving long distances a reasonable choice (as long as you ignore how it’s unpleasant and has lots of terrible externalities). Change the incentive and people will make different choices.

          1. Carol Becker

            I would say 82.4% is a “vast majority.”

            As to incentives, what incentives would you place on me so I would 1) give up my job 2) give up the best education I could for my child 3) stop having my child see her grandparents 4) stop taking care of the elderly folks in my life 5) stop having my daughter chase her sports dreams and 6) stop having old dogs who will pee on the floor if they are not let out during the day?

            It isn’t a matter of incentives, it is a matter of geography. If you want more transit, then get in bed with big developers to bring more jobs into downtown. If you want to reduce travel for children, stop wanting integration of schools and dealing with concentrations of kids by race and go back to neighborhood schools. Incentives do nothing. We can play SimCity and bulldoze large swaths of the City and remake them in our dreams, if we can find the literally tens of billions of dollars to do so. Until then, you have to either admit that someone like me cannot live in this dream or change the dream so parents and kids and old people and lots of other folks can live here too.

            1. Adam MillerAdam Miller

              Considering how much time you already spend in a car, which seems like a big disincentive itself, that’s a good question.

              Serious question that’s not intended as snark, but may sound like it: what is it you value about living in a city?

              Because personally, not having to start my day with an hour of driving is one of the considerable advantages of urban living. But were I to find myself having a kid in school in the suburbs along with my primary child care, I’d probably think about housing in the suburbs closer to those things just for the time savings alone.

              But that’s me. Why do you prefer to live in the city?

              1. Carol Becker

                I live in the City because I like my neighbors. I like my house. I like access to restaurants and parks. I like access to my family. My friends live here. I like the diversity of people and experiences as I get bored easily. (I am sure you are surprised by that.)

                If you want to avoid an hour of driving, then why are you making driving harder for other people? Why don’t they deserve the same thing you want? All of these narrowing of streets, taking away parking, building housing without parking – it all means that people are stuck with the thing you do not want. Why make them live like that?

                I say that because my kid has been at MCAD camp this last week and fighting to get there has been horrid. I literally did spend an hour getting there. There are literally miles of traffic jam on Franklin, even away from 35W. Uptown is horrid. Narrowing 26th and 28th has push traffic off to these other streets and it shows. Blaisdell and 1st are awful. All I could think about was how this was by design and no one thought about the kids that were waiting for their parents and the jobs that were not getting done and how money was coming out of these people’s pockets and the loved ones waiting. Because someone – some planner – didn’t care about these people’s lives but instead said that bikers and walkers and transit users matter but they do not.

                1. Adam MillerAdam Miller

                  Driving north/south in the city is a terrible pain right now because 35W is being fixed so it will work better for cars and we unfortunately built it in the first place so people rely on it. East/west is also an issue because the bridges over it need fixing, although 26th and 28th have been pretty reasonable during this extreme construction season, except its way harder to speed on them than it used to be.

                  I still don’t understand what you value about the city, though. In a car, you’d still have access to restaurants and parks and your friends (indeed you tell us that’s the only way you access them now).

                  Making it marginally harder to drive and marginally easier to not drive is how we make the city a place to be instead of a place to drive through. We’ve got lots of suburbs to be the latter. Only the city can be the former.

                  1. Carol Becker

                    If it were true that it were marginally different, it would not be an issue. When you literally close down lanes of traffic and create artificial traffic jams, when you do it throughout the City, it isn’t marginal any more. When Franklin Avenue is pretty much impassible. When the traffic on Plymouth Avenue bridge (the one further west) is so backed up on a Saturday afternoon that it is backed up all the way across the bridge to where you get on the bridge. When it takes an hour to go from my house to Lake and Nicollet, that isn’t marginal any more. Maybe you haven’t been out in the City lately because you are on your bike but it is becoming horrible. I have been taking pictures. I can’t post them here in this post and Streets.MN doesn’t seem to want to publish my stuff but maybe I will over at E-democracy so you can see what I am seeing.

                  2. Adam MillerAdam Miller

                    35W is effectively closed and something like half the bridges over it are out. Of course it’s hard to get around right now, but bike lanes have nothing to do with it.

                    1. Carol Becker

                      Lane closures called bike lanes have a lot to do with it, even miles from I-35W. Narrowing Franklin has a lot to do with it. Narrowing other streets like Blaisdell has a lot to do with it. Narrowing bridges has a lot to do with it. I appreciate that if you just ride your bike to and from work that you probably not getting around the whole city during the day but if you did, you would see how bad it is. And it has been made this way deliberately by bad planning from the City. It is a policy choice to make people’s lives worse.

              2. Carol Becker

                Here is a more honest answer. I grew up in North Dakota. The biggest city I ever saw was Fargo. It was the big city for me. I wanted to go to college at a small private school but my dad told me I had to see the world. He made me come to the U of M. I had never been here before nor had any sense of how big it was. I told my dad to just drive to the middle of the map.

                He dropped me off for orientation, which you were required to stay overnight. I was standing in the first line, to get your room, telling dirty Norwegian jokes where I met two of my best friends.

                After we got our rooms, they asked me what I wanted to do now that I was in the big city. I told them ride escalators, because North Dakota does not have them. We went to Daytons and rode nine floors. We then ate at Estibans on Hennepin and I got to watch my first drug deal go down.

                I think it was then that the bug bit me. How do we live together in this small space? What are the right things to do and which are the wrong? How do we make decisions as a society? I got my undergraduate degree in Urban and Regional Affairs, my Masters from Humphrey with a concentration in planning and my doctorate in Public Affairs.

                During most of my undergrad, I would learn the City by riding my bike up and down one street until I knew it. Then I would branch off onto another street until I knew that one too. That is how I learned the City. University. Central. Rice. Nicollet. Etc. I asked to see the slums and was pointed to a place on a map and rode up to North Minneapolis and was confused because it looked just like old houses where I was from and not Cabrini Green like the TV showed. Maybe it was that moment on Hennepin Avenue. Maybe something else.

                How about you? You are a lawyer. Why do all this?

                1. Adam MillerAdam Miller

                  That’s a really fascinating response, Carol.

                  Because I grew up in the north suburbs, very much in drive everywhere land, and only moved to the city to go to the U too. I graduated and moved to D.C. for law school and only came to “urbanism” via wandering the streets of DC and then Minneapolis again and realizing that the “slums” aren’t really any different from the rest of the city. The key being to get out of a car an experience them on foot or on a bike so you can see that people are people. Neighborhoods that I learned as a kid to avoid I bike through all the time now, because it’s just not a big deal.

                  I do this because the city is great and a better way to live, less dependent on cars. People should experience it and see how car-dependent, suburban lifestyles aren’t sustainable or even desirable

                  1. Carol Becker

                    So let me ask you this – if you really believe this, why did you move into a neighborhood that does not support what you want? You own cars and you clearly need them to live in your current house. Why not just move to a place that lets you live as you want, walking and biking for the vast majority of your life instead of a bungalow community that does not?

                    And you have a kid, right? How do you arrange your life in Minneapolis without a car?

                    1. Adam MillerAdam Miller

                      We bought our house where we did exactly because we can do most of what we need without a car. We’re four blocks from a grocery store and a few places to eat. I can bike or take the bus to work. I can stop for groceries on the way home, or walk or bike over when needed.

                      It would be great if we could add enough neighbors to also add a pharmacy, but I can also always walk over to Target or Walgreens when I’m downtown.

                      I use a car about once a week for a larger grocery run (unless I decide to use the cargo bike instead). As a family we sometimes use the car to go to Grandma’s house or out. When she’s old enough for school, the local,one is close enough that I hope to mostly be able to take her by bike.

                      It’s really not that hard to drive less if you make an effort and prioritize it.

  5. Scott

    Mobility for whom? What about children, poor people, the disabled, seniors who probably shouldn’t be driving due to poor eyesight, etc? There are a lot of these folks in Minneapolis plus others who don’t want to drive a car for absolutely every task. Cars are also expensive to own and maintain costing thousands of dollars each year.

    Plus, there is a public transit system that could be a lot better if so many resources weren’t directed towards subsidizing people who drive. As a blind person, I find it discouraging when City residents act like it is impossible to function as a human being without a car.

    The point of this post is that we dedicate a lot of space and resources to storing cars, which encourages people to drive more. Why can’t we make it slightly less easy to drive, and direct more resources to transportation choices making them more appealing?

  6. Bill LindekeBill Lindeke

    I removed a few comments where were becoming overly personal. It’s possible to chat about cars without interrogating the lives of specific people.

  7. Andy Wattenhofer

    “And an autonomous car wouldn’t be an exception to this math.”

    It would, actually. We wrongly assume that autonomous technology is somehow just a drop-in replacement for humans. But it is changing how we use cars. There are two ways that autonomous technology will make said cars an exception to the math:

    1. They don’t need to park when they’re out working. Not on the street, not in a garage or parking ramp, and not at a store. The false assumption is that people will continue to own cars and store them when not in use. Maybe some will, but there’s not reason for it to be sitting idle most of the time. They can be hired out for others to use, or to deliver packages, or whatever we can put them to use with. More likely is a Car2go and Uber type of model, where a company operates a fleet and we summon a car with a phone app when we need one. Those cars only need to park for maintenance at some central facility.

    2. Autonomous tech makes cars more efficient in space usage. They’ll be able to communicate with one another to alert others of obstructions, and the technology allows them to see further ahead and more accurately determine conditions. They can follow more closely because they can communicate stopping events. So instead of where you have a cascade of flashing brake lights down a line of cars, the human reaction time is eliminated and all the cars brake at the same time. This technology is already being developed. Cars already come with automatic braking, so the next step is that they send a signal to surrounding cars to brake and it all happens faster than a human could react to the flash of brake lights ahead.

    1. Christa MChris Moseng Post author

      What I said was “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.” The counterexamples you offer don’t contradict this statement. They suggest that autonomous cars will take up somewhat less space per car, on average, not that the cars themselves will ever consume only exactly as much space as they occupy.

      Moreover point one assumes that people abandon private car ownership for autonomous taxis. However, there is simply no reason to assume this will come to pass. It certainly isn’t in the interest of automakers, and it isn’t compatible with how most car operators currently use private automobiles.

      People use their cars to get to work… generally all at approximately the same time. All the autonomous taxis we’d need to handle the times of peak capacity–something like 18 hours of every day–are going to have to park somewhere when they’re not being used (or are they just going to drive endlessly? wait, they have to also be fueled/recharged).

      Autonomous cars therefore just have their own unique infrastructure and parking needs, they’re not an exception to the need for the space they consume. Maybe they can consume somewhat less space on average per vehicle due to added efficiency, but even in the most utopian scenario they still require vastly more space than other modes of transportation.

      People also store stuff in their cars It’s going to take a major culture shift in America to adopt the autonomous taxi as the primary mode of transportation. And if we’re going to do that, let’s shift them to something even more efficient.

      Point two, I concede, but a moving car still needs a stopping distance as a matter of physics. Sure, take out the human reaction time and the amount of space is smaller, but it still requires more space than it physically occupies, which is what I said.

      Overly optimistic estimates of the amount of space they might save, assuming all relevant eventualities work out perfectly (they won’t) is one more reason on my list to be deeply skeptical of the promise of the autonomous vehicle future. (Let’s start with can they drive in snow.)

      But let’s say it all works out and everyone starts using autonomous taxies instead of private automobiles. GREAT. We definitely don’t need on-street parking then and can reclaim all that space.

      1. Adam MillerAdam Miller

        An obvious problem for 1 is that there’s way, way more demand for car trips during rush hour. During the rest of the day, we won’t need a fleet of that size and the extra cars are going to have to do something – either move around empty or park. If it’s move around empty, we’re going to have serious congestion problems.

        And that’s without challenging what I think are overly optimistic about the efficacy and proximity of adoption of transportation as a service.

        1. Andy Wattenhofer

          And what if they park? Do they park on residential streets, driveways, garages, or retail parking lots? Do we need to continue to maintain all of that space for car services? That’s the point here. It’s not that they don’t need to park, it is that they need fewer parking spaces and the proximity of those spaces to homes, stores, and attractions is less important. It’s no different than an Uber driver dropping someone off at a bar, really. It’s not like they wait for you in the parking lot. Uber and Lyft are transportation as a service, by the way.

          1. Adam MillerAdam Miller

            Yes, hey canndrive to remote parking places, which is good for urban space that can be repurposed, but that’s even more miles traveled.

  8. Andy Wattenhofer

    Fair enough, your statement about autonomous cars only applied to the 170 s.f. of physical space that the car occupies at a moment in time.

    The rest of what you wrote, well, you’re falling into that trap of assuming status quo except that the car drives itself. Let me rephrase a few points then:

    1. People who opt to own a car can still do so with autonomous. Some percentage of them will share them much the same way as with Uber and Lyft drivers, except they don’t need to be driving them! Net effect: fewer cars, less need for parking space.
    1a. I don’t know why it is sacrilegious in this country to suggest not owning a car. But, if you could just pay for use of an autonomous car through a service, only when you need it, not having to worry about maintenance, insurance, fuel, and storage, and it is cheaper, why would you choose to own one exclusively? To store your junk in it I guess? Yet any time I suggest the idea people dig in and oppose it. Never mind. It will come to pass when people can start to realize the benefits. We already have younger generations opting not to drive, so maybe it’s already happening.
    2. Off peak hours, autonomous cars do not need to park in driveways, garages, residential streets, or Target parking lots. They can be off doing other things, such as delivering parcels, getting maintenance or recharging at a central depot, or taking off-peak passengers. It’s likely too that off-peak pricing will be lower, causing more people to opt for service off peak, and usage patterns shift. Anyway, –> Less need for parking.
    4. It is definitely in the interest of the car manufacturers to have as many people as possible buying cars. But Google, Uber, and Lyft are not car manufacturers. They’re the ones who will push/are developing autonomous car services, and there will be others. Those companies have every interest in eliminating the most expensive and inefficient part of their operations: drivers.

    You suggest that I am overly optimistic, but any one of these things coming true even fractionally will result in less need for space dedicated to parking. What is wrong with that?

    Also, if you haven’t already, check out the book “Happy City” by Charles Montgomery. He covers a lot of ground on the topic of urban space devoted to cars.

    1. Adam MillerAdam Miller

      Regarding 1a, there’s a ton of status signaling in car ownership. Look at the car buying choices people make or suggest that people drive less and you can see it.

      Regarding 4, self driving car optimists are much more convinced than me that network operators are going to want the capital costs of owning the fleet. At least as long as there’s stutus in car ownership, I think they’d rather copy Uber and Lyft and let others own the cars.

      Maybe that will change over time if people aren’t willing to buy, but that’s gotta be how it starts.

    2. Monte Castleman

      To store your stuff in, yes. I don’t leave boxes of junk in there for months at a time, but I store my bicycle, swimming suit / towel, a case of bottled water, and inline skates in the car all summer, in the winter I store my parka, ice skates, and snowshoes. Or when I get home from a road trip after midnight I can just go to bed and deal with unpacking everything in the morning.

      Also, there’s a pride in ownership, I like looking at my shiny green SUV, and knowing that it belongs me. And I know the person sitting in the seat before me doesn’t have a bad case of the flu or something.

      It should also be noted that people don’t always pick the cheapest option, as convenience and comfort have a benefit that offsets the additional cost. If people always picked the cheapest option there’s be a lot more people bicycling in the snow and rain, or sitting next to strangers on the bus, or driving a small city car during the week and renting an SUV or pickup for the weekend hauling tasks rather than just owning one and driving it empty to work during the week.

      I’m skeptical that a TaaS vehicle won’t be much cheaper unless you want to give up your privacy and potentially your safety and go to a shared taxi model. Figure during rush hour a TaaS vehicle can make a maximum of two trips from Burnsville to downtown, and there’s the cost of the likely empty backhaul between trips. That they might be cheap overnight doesn’t mean that they’ll get utilized. How many packages need to be delivered overnight (and isn’t leaving a package on a doorstep at 3:00 AM a thieves dream?). Since I own a vehicle it would cost me almost nothing to go get ice cream at 3:00 AM, but that doesn’t mean I want to do it, and I wouldn’t if a TaaS vehicle was cheap at that time either.

    3. Christa MChris Moseng Post author

      I think it’d be great if all the most optimistic futurism about self driving cars comes to pass, because it would be better than what we have now. However, I don’t think we should plan around those most optimistic assumptions ever coming to pass.

      This tweet and the quoted tweet assessing the underlying the quoted article sums it up better than I can in a comment box. https://mobile.twitter.com/Catfish_Man/status/1021593779902410754 Cars still take up space, even if they drive themselves.

      1. Andy Wattenhofer

        It is baffling to me that after an article titled “A Modern City for People Would Devote Less Space to Cars” that all of the comments are defending the status quo of cars taking up space. It does not need to be debated that autonomous cars take up space; we know that all physical objects take up space. It is that the technology permits them to use *less* space. That’s less space devoted to car infrastructure. It is not about whether autonomous taxi services are viable or whether people will choose to own an autonomous car or use a service. That topic would take 20 articles and it includes social and emotional factors that can’t be distilled into simple points. The plain, simple fact here is that a modern city devoting less space to cars could do so *in many ways* with the technology availed by autonomous cars.

        Now excuse me, I’m going to go argue the value of getting a smart phone with my mom.

        1. Adam MillerAdam Miller

          I certainly hope that you’re right that autonomous vehicles will allow drastically less space to be allocated to cars but I’m skeptical. Not least because I’m worried about drastic increases in vehicle miles travelled, and moving cars take up even more space than stored cars.

          I guess if that’s true, then the best case scenario is congestion, but I worry that will lead to pushes to devote yet more roadway to cars.

          And in this autonomous vehicle discussion, I don’t think anyone is defending the status quo, but rather unsure that the robot cars are going to save us.

            1. Andy Wattenhofer

              No offense, but those articles are six years old, an eternity in terms of technology. Millions of miles have been logged with autonomous cars since then, gathering petabytes of data that are fed back into development. So much has changed since 2012.

              The fundamental mistake that people make is that they assume autonomous cars are an over night, drop-in, all-or-nothing replacement for existing cars. The fact is that autonomous technology is being incorporated into cars now (automatic braking, lane departure correction, self-parking, proximity sensors, speed control, data logging), and it will continue to be. And the behavioral shift is already in play with new transportation sharing models such as with Uber, Lyft, Car2Go, Turo, Getaround, and Maven. It’s not happening over night. It’s not happening with people simply waking up one day and replacing their existing vehicles with Uber service. And not everyone will use autonomous cars the same way, or for everything, or at all.

              1. Christa MChris Moseng Post author

                I want to bring this back to the very top of my article: assuming the most optimistic autonomous car future, how is the amount of space devoted to cars on the Starbucks lot changed? (Or on Marshall, as they line up to get in the lot?)

                Will we have more demand for drive throughs, or less?

                1. Andy Wattenhofer

                  The most optimistic outlook in terms of space usage is that there is almost no need for parking on site. A car that is sitting idle is not making money, and even if the car is owned by an individual rather than a service, they have every incentive to share it out like with Uber so they can make money from it. Of course there will be some people who will not share out their cars, but if we’re being optimistic then those people are almost non-existent. So the need for on-site parking is almost eliminated.

                  In today’s setup, cars and their associated insurance and maintenance costs are paid for on monthly or yearly plans regardless of how much they are driven. But if people are paying for car usage per unit of time, then they’ll be less willing to spend time waiting in line for coffee. People suddenly have an incentive to maximize the efficiency of their transportation time. So behaviors will change there and we could expect fewer people opting to wait at a drive-through.

                  On the flip side, we should expect that vehicle trips will increase in number, both per person and in numbers of people (children, blind people, pets, or anyone who couldn’t afford to buy a car before). That doesn’t necessarily mean more cars on the road at any given time, which is a mistake in logic that people tend to make. There is a lot of slack in the system right now, lots of idle capacity from cars that remain parked for the majority the time. If we automate it and optimize the dispatching software for maximum efficiency, it could even be possible to reduce the number of vehicles in use at any given point in time. Either way there’s no way I can think of to predict what the effect of all this would be on a drive-through. It could increase demand or people could abandon it in favor of a more efficient option.

                  One thing I am certain of is that cars wouldn’t wait in the bike lane. If it is not a designated driving lane, cars won’t go there. So there’s a win!

                  None of this gets to what is probably the technology with the greatest potential to change things: machine learning. These cars are continually gathering data and feeding it back into the system. We could have near real time mapping updates. Over time, every possible situation between cars and pedestrians and bicyclists will be documented and learned. What if every car could bring all that knowledge to bear? Would we even need drive-throughs?

                  1. Adam MillerAdam Miller

                    1 and 3 can’t both be true. Demand is so lumpy because of rush hour that I don’t think you can have enough capacity to get people to and from work and also not have significant excess capacity during the rest of the day. That capacity either sits idle or makes a bunch of extra trips (e.g. to storage). Meanwhile, there will be an interest in sending empty vehicles to wait in drive throughs.

                    I’m also uncertain about your certainty. Cars won’t wait in the bike lane if they’re programmed not too, but there will definitely be pressure to allow them too.

                    1. Monte Castleman

                      The spaminator munches my comments if I try to post links, but I agree that any kind of load balancing is not going to happen. The demand based on time of day chart looks like a volcano, with a total value for the day of 1, demand at 4:00 AM is .005 and demand at 5:00 PM is .079. So there’s something like 16 times the demand then.

                      If people aren’t going to work at 4:00 AM now I don’t think self-driving cars are going to change that. Sure you can have pricing incentives with self driving cars tomorrow too, but getting to drive on the freeway with no one else around today is an incentive too. Most of the people driving at 5:00 PM are making mandatory trips home from work at that time, not making shopping trips that they could do at 4:00 AM. I already don’t go driving around the metro at 5:00 when I don’t absolutely have to due to congestion.

                    2. Julie Kosbab

                      Links tend to be embargoed. When we see it happen we clear them. It’s not always immediate though!

                      (Even happens to Moderators. Found a Mod comment sitting embargoed for links the other day.)

                    3. Andy Wattenhofer

                      Today there are millions of cars that on a given day only take a single person to and from work. Some large number of those could take additional passengers on additional trips, and yes, they could do so during rush hour. That is proof enough that we have extra capacity today. We have individuals making optimal choices for themselves that are suboptimal in aggregate.

                      When we put the logistics in the hands of car sharing services, it becomes a software problem. They can optimize for maximum utilization in ways that individuals cannot. They can plan trips and dispatch vehicles more efficiently than any individual.

                      And since the question was phrased to assume the most optimistic autonomous car future, we’re assuming that high demand means higher price. You’re damn right that people will adjust their usage habits if they can get a lower price at another time. So optimistically, those rush hour peaks flatten out.

                      And we haven’t even gotten to the matter of rush hour traffic and the dumb things that human drivers do. Traffic jams occur because people are selfish and incompetent. If you remove the human elements, throughput on the roads can improve vastly.

                    4. Monte Castleman

                      Sure there are millions of cars that people currently drive alone, but is that due to things that will change, like the logistics of finding a passenger, or things that won’t change, like the security and privacy driving alone has?

                      You can still get stabbed and robbed in a self-driving car, or someone could cough on you and give you meningitis, or even just annoy you with a 30 minute conversation on why they hate the Twins.

                  2. Monte Castleman

                    Considering the mess some people make in cars, or that some people might have a bad case of the flu, or the people that might steal belonging left in the trunk while your car is loaned out, I think the people that will want to keep their car to themselves are going to be pretty significant in numbers. Not everyone does everything possible to make spare change, witness the number of people that just donate their old stuff to Goodwill rather than try to sell it.

                2. Monte Castleman

                  Probably a lot more demand for drive-thrus.

                  1) A lot more people than today will be able to enjoy the freedom cars provide- the elderly and handicapped for example- meaning more cars to potentially use the drive-thu

                  2) You’ll be able to send your empty car into the cold and sleet to go fetch a cup of coffee and bring it back to your house when you might not want to haul yourself out to do it today.

                  1. Andy Wattenhofer

                    You’re describing a coffee delivery service. There’s no reason that coffee needs to come from a drive-through on Snelling.

                    1. Monte Castleman

                      Where else is it going to come from? You can’t brew it in Elko or it will be cold by the time it gets to St. Paul. If you put something that generates dozens of trips an hour next to a single family home a block away the homeowner is probably going to object to it as much as s/he would living next to a six story apartment tower.

                    2. Andy Wattenhofer

                      Elko? That’s a leap. You’re being ridiculous. There are many places in St. Paul that can provide coffee, not all of them are on Snelling, and not all of them have drive-throughs. But sure, set up your coffee delivery service in Elko and make all of your delivery cars wait at the drive-through.

                    3. Monte Castleman

                      OK, so where then in St. Paul should they go? Someplace that generates a that amount of traffic should go next to a street that can handle that amount of traffic. Like Snelling Ave as opposed to a next to a single family house. And if you have a half dozen self-driving cars showing up to pick up up coffee to ferry to their owners, stacking them end to end in a drive-thru while they wait they don’t take up any more room than if they all pulled into regular parking spaces and waited side by side.

          1. Andy Wattenhofer

            More miles driven does not necessarily correlate to more space required. Total trips taken will certainly increase with autonomous cars, if not simply because more people will have a car as an option (my dog, my blind friend, or my immobile grandparent). But it’s important to consider something we know about roads and capacity already: adding lanes does not always increase capacity. There’s a diminishing return on investment in lane expansions to the point that they tend to just add congestion.

            Much of the reason we need so many roads are human factors. People are inefficient. I live in NE Minneapolis, where all of the main thoroughfares are four lanes wide, with the outer lanes only being used by people to go around the cars making left turns (we need three lane roads in NE!). People don’t know how to efficiently use brakes, and they drive too fast for their own abilities. The react too slowly, and sometimes they don’t pay attention. Worst of all, people have terrible depth perception when driving. All of these things are moot when you remove the human. In the least, we can get more bike and pedestrian space out of the roads we already have if we can remove the human factors of driving.

            1. Adam MillerAdam Miller

              Adding lanes does increase capacity. It often doesn’t reduce congestion, because more cars show up to use that additional capacity, getting you right back to congestion. Nonetheless, there are more cars in that congestion than there were before.

              Yes, autonomous vehicles can use existing space much more efficiently than human drivers, especially as we project out into the future where they’re talking to each other. Maybe that’s enough to fully offset a lot more miles travelled, but I don’t think anyone can really say that with great confidence.

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