Episode 92: How Housing Influences Transportation Choices with Adam Millard-Ball (Road Scholars pt. 2)

Madeline Brozen 0:05
Hello, this is the UCLA Housing Voice Podcast, and I'm your host, Madeline Brozen. This is the second part in Road Scholars, our interlude into the transportation research world and its connections to housing.

For round two in the series, today's episode is a re-airing of a perfect fit from three years ago of episode 22 with Adam Millard-Ball entitled How Housing Shapes Transportation Choices. This conversation covers research that helps to answer some important questions policymakers often wonder: Does someone drive less because they live in a building with limited parking? Or do they live in a building with limited parking because they drive less? Adam's work is particularly useful because it uses an approach that social scientists just don't get to do very often, where participants are randomly selected to be in certain groups and then have their outcomes followed. This experiment takes place as a part of San Francisco's Affordable Housing Lottery, where the people who are successful in getting selected for housing to receive an affordable housing unit are then assigned randomly to buildings with different levels of parking and in neighborhoods with different levels of transit service.

Before we turn the dials to Shane for this re-airing, I want to dedicate this episode in our Road Scholars series to the late Donald Shoup, who passed away earlier this year. Don was the author of The High Cost of Free Parking and was the first person who brought attention to the issue of how parking requirements and housing run counterproductive to everything good, change people's behavior, and just make what we're trying to do with infill housing, climate goals, and the making of good cities just less effective. Throughout his long and storied career, Don took the topic of parking from relative obscurity to an interesting and hugely important one. All due respect to our esteemed guest, but I feel confident that Adam and many other scholars wouldn't be able to do this work on the critical housing and parking connection without Don Shoup's foundation. It's my great honor and sorrow to dedicate this episode to his work, family, and memory. I am incredibly fortunate because I got to be his student, colleague, and friend.

Stay tuned this fall for details about UCLA's celebration of his life. With that, here's to you, Shoup Dogg, and now today's conversation with Shane Phillips, Mike Manville, and Adam Millard-Ball.

Shane Phillips 2:40
Our guest this week is Adam Millard-Ball, Associate Professor of Urban Planning at UCLA. Adam joined our faculty, I think about a year ago, and we're really excited to finally have him on the podcast. Welcome to the show, Adam, and a belated public welcome to UCLA.

Adam Millard-Ball 2:56
Thank you. It's really nice to be here. This is my first ever podcast, so I'm excited to do it.

Shane Phillips 3:02
Yes. Mike Manville is our cohost today, so welcome, Mike.

Michael Manville 3:06
I'm glad to be here cohosting, and I, like you, am thrilled to welcome Adam to the podcast. He is a top-notch transportation researcher, a top-notch environmental impact researcher, so UCLA is lucky to have him, and the podcast is lucky to have him.

Shane Phillips 3:23
We're going to open the podcast, How We Always Do, with a question about where you're from, somewhere you love. I think you said you're going to do San Francisco. If we were visiting, where would you take us? I think we've all been there before, but maybe you have a special insight having lived there.

Adam Millard-Ball 3:38
Sure. I grew up in England, as might be obvious from my voice, and joining a new university in the middle of a pandemic isn't the best recipe for getting to know a new city very quickly. So I'll say a few words about San Francisco, which is probably the place I've lived longest in the US, and it was actually the first place I lived in California when I moved to the US. At that time, there was this big freeway that loomed over Market Street, the central freeway. It had been closed since the earthquake, but it was still up there. And if I was taking you on a tour, I'd like to show you that neighborhood and really what an amazing difference it makes to remove that freeway, not just in terms of it coming down, but also in terms of what the city did with that right of way. Because I think the temptation for some like former road rights of way or former freeways is to say, let's make it a park, let's make it something that's going to offend as few people as possible. But in San Francisco, it was remarkable how much they turned over those former freeway parcels into housing, and half of them into affordable or supportive housing. And even the interim uses, there was a farm there for a while, it was truly an urban farm as an interim use until the housing came online. And we'll talk about parking, I'm sure, in quite a bit, but it's also one of the first places that San Francisco pioneered removing parking requirements and introducing parking maximums.

Shane Phillips 5:13
Yeah, I think I've actually visited that on a tour during some conference I was at in San Francisco. So your article was published last year in Urban Studies, along with your co-authors Jeremy West, Nazanin Razaei, and Garima Desai, and it's titled, What Do Residential Lotteries Show Us About Transportation Choices? I will admit to a little trepidation about discussing this paper. Not because it isn't great, because it really is, but because the findings are so straightforward and we have 45 to 60 minutes to fill. But to set this up a little bit, for a long time, researchers and practitioners have assumed, I think understandably, that the environment people live in shapes the choices that they make about how to get around. But it was really, really difficult to be sure, or to know the size of that effect, because we know that people choose where they live based on their preferences. So on the one hand, maybe people drive less because they live in apartments that don't provide on-site parking, and on the other hand, maybe they live in apartments that don't provide parking because they drive less. The same goes for access to public transit and walking and biking. That's a selection bias problem that looms really large in this type of research, but in this paper you found a really clever way to bypass it and to isolate the impact of the built environment itself. And in doing that, you've developed some very strong evidence that less parking and better transit really do cause people to drive less, regardless of their personal preferences. So that's my very quick summary of what you found and why it's important. But now let's just take a step back, and I'd like to have you set this up for us. There's a ton of research examining the relationship between the built environment and people's transportation choices. What did we know going into this study, and what did we merely think was true but couldn't really be sure of?

Adam Millard-Ball 7:11
So something we know a lot about before the study and after the study, and there's literally thousands of studies, perhaps even tens of thousands of studies on the link between the built environment, so how walkable neighborhood, how much transit, how dense, what's the mix of uses, and how people get around. And so there's pretty consistent findings that emerged from that research that, yeah, in dense mixed-use walkable places, people drive less, where transit is better, people drive less, in walkable neighborhoods, people drive less. And so there's a lot of evidence to support that. And so you might think, okay, why did you need to go and do the study? But there's been this nagging doubt, how much of this relationship is due to that type of self-selection that you just talked about, and how much is a causal impact? How much is people who like to walk or like to ride the bus moving to walkable transit-rich neighborhoods? And how much is the built environment itself exerting a change on how people decide to get around? And then what I think is particularly missing from that literature is the role of parking. And it seems to make sense intuitively that if you have more parking in a building, people are going to own more cars and people are going to drive them more. But that's really hard to demonstrate in practice for a couple of reasons. First, the data density is really easy to measure and obtain. Parking data is a notorious pain to get and to manage. Like very few cities know how many parking spaces there are in their buildings. Many transportation planners who should know better do surveys that don't even ask people how many parking spaces are in their building or do they have parking at work? And then secondly, the self-selection problems certainly happen at the neighborhood level. You choose a neighborhood based on how good the transit is, how good the walkability is, how good the car access is. But there's lots of other reasons why people choose neighborhoods. It could be schools, proximity to friends, family, everything else. Whereas parking, it's much more granular. It's at the building level. So if I have a car or two cars, I care much more about the parking when I'm looking for somewhere to buy or to rent. If I don't have a car, then I'll go for the cheaper apartment that doesn't come with parking, if that's available and to the extent that the market provides that. And this is somewhat of a sidebar or one of my gripes so far about Los Angeles and someone looking for housing in Los Angeles. It's so difficult to find an apartment that has less than two parking spaces and no parking spaces at all. And for me, as someone who doesn't want that second parking space, I resent having to pay for that.

Shane Phillips 10:09
Yeah. But that's the key is as a transportation researcher, you understand that you are paying for it, whether it's a separate charge or not. It's just that the cost is baked into your rent. So that kind of gets at my next question here. This is the UCLA Housing Voice podcast. We're not focused on transportation, even though we really care a lot about it. So why as housing researchers, as people interested in housing affordability and access and these other things, why should we care about this question of what influence parking and the location of housing and its built environment has on the way that people get around?

Adam Millard-Ball 10:50
Well, from a housing point of view, transportation is one of the factors that drives housing costs. And I hope that Mike can weigh in a little bit because it speaks to much of his own work. But many of the infrastructure costs loaded on to housing developers. And so if you think there's going to be more traffic or you think parking demand is going to be higher than cities are to the developer, not just to provide more parking, but perhaps to widen the street or to widen the intersection, add a turn lane as a condition of approval and signalize an intersection. And so to the extent that traffic impacts are inflated for new development, that drives up the cost of that housing because it's forced to pay for much of that infrastructure. And then there's also just general public policy reasons, I think to care about the impacts of policy decisions in order to do a better job in planning in the future. And then it also affects the design of grant programs. So some funding, some grant programs increasingly are tying housing funds to reduce climate impacts, to reduce car travel. This type of study, I think, is important in helping refine their methods and criteria.

Michael Manville 12:08
Just to add to what Adam's saying there, which I think is exactly right, you know, particularly with respect to parking, the parking requirements that are put on housing, especially housing that would otherwise be infill, is often what we call the binding constraint on density. You know, there's plenty of examples throughout cities across the U.S. where you have a parcel that if you look at the allowable density in the FAR, you could say, oh, well, you could put 15 or 20 units of housing here. And then you realize that because of the parking requirement, either your budget or the site geometry, once you accommodate that parking, actually, you can really only put 12 units of housing or 14. And so what's really reducing the housing supply is that parking requirement and to a certain extent, that's a little bit harder, I think, to quantify these other situations where, for instance, you surrender some land to widen the street or widen the intersection. I think you can have a beef with that on two levels, right? The justification of these mitigations, the parking requirements and so forth, when it is spelled out, and these rules have been in place for so long that at this point, often they're not spelled out. They're just there. But when it is spelled out, it is this assumption that, well, you're going to put this building there, everyone's going to drive, and when they drive, they're going to congest the street, they're going to congest the curb, and so the developer has to accommodate that. On one hand, I think in a better world, we might be able to say, well, so what? It's okay if a housing development goes in and the street gets a little bit more congested. Maybe we prefer that you have denser development and we're willing to tolerate more congestion.

Adam Millard-Ball 13:51
It's a transportation tail that just keeps whacking the housing dog.

Michael Manville 13:56
Exactly. So maybe we should flip that around and housing should become the dog that controls its tail. But even if you don't, if you don't accept that and you say like, no, I mean, the transportation tail should continue to be the influence, I think the findings that we're going to discuss and that have been hinted at prior to Adam's research but that he maybe demonstrates more conclusively is that actually, even if you worry about development creating more driving and new congestion, it turns out that these mitigations are perverse, that putting in more parking and widening the street doesn't mitigate the sort of fixed amount of vehicle travel that would have happened. It actually encourages more of it, right? And so even on the terms that a development opponent might frame this, our understanding from Adam's research and other research like it is that, well, no, even from that perspective, this is counterproductive. I think maybe also we should talk about, there's two things going on when we talk about this selection bias question. There's this issue of are people finding the housing they want, right? Like if I'm someone who just doesn't really want to drive or like Adam was saying, he's someone who arrives in a city and doesn't want two parking spaces, does the built environment as it's constructed right now, let me satisfy that preference. And the fact is that in a lot of the country right now, if you're someone like Adam who doesn't want those two parking spaces, it doesn't. And so there's a potential thing going on when we talk about selection bias that's saying, oh, you could build housing like this, but you're not going to change anyone's behavior. What you're going to do is redistribute people who just didn't want to travel in a particular way, away from housing that didn't suit them and towards housing that does. And then there's an extra level that I think really is much more the obsession of the social scientists, which is, did you with a good identification strategy demonstrate that you took someone who in any other circumstance would be behind the wheel of the car and make them into a pedestrian? And I would like to hear Adam talk about this a little bit more because I think for a long time, self-selection just dominated transportation seminars. Like you could just read someone if you weren't paying attention in a presentation, you could raise your hand at the end and still sound smart and be like, well, what about self-selection?

Adam Millard-Ball 16:26
It's like you just want to make a comment that tries to undercut the speaker and you say, haha, but have you thought about self-selection?

Michael Manville 16:33
Exactly. Right. I mean, it was just it was a way you could space out and still kind of like come in with a zinger at the end because that's what petty academics do. But I think if you're not an academic, you could, if not an academic, you might not think about this at all, but you could think about it and then say to yourself, well, I wonder how much this matters, right? Because if we do have a shortage of housing development that that's amenable to people who don't want to drive much, like, does it matter if what we're doing is just helping those this preexisting group of people who don't want to drive find a place where they don't want to drive? Right. Or is it really an extra important to say, no, this was going to be a driver and now she's a walker? So I don't know. I'll let Adam take that away. But it's sort of I think it's a question that sort of has been kicked around for a long time.

Adam Millard-Ball 17:18
Yeah, I agree completely. And I think they're two separate related, but both important questions in themselves. And absolutely, I don't think it's that controversial to say that public policies that make people happier are a good thing. Take it back. And so if some people like living in a walkable neighborhood and don't want to pay for a second parking space or any parking space, and they don't have access to that housing right now, then building more of what people want, like it's absurd that cities are standing in the way of that and forcing the developers to build products which are really not what people want. And unless there's concerns on, say, like building safety or things like that.

Shane Phillips 18:03
It's sort of like a two step or two phase issue where it's like, let's first just satisfy everyone's existing demand. Like we're not even there yet. And so this question, while important for people who have different preferences, is this enough to change their behavior in ways we deem socially beneficial? Like it's an important question, but it only becomes really important, I think, after we've built enough of this type of housing so that people who have a preference for walking more, biking more, taking transit more. I realize I'm sort of undercutting the importance of your findings here as we're talking about, but like it is really important.

Adam Millard-Ball 18:42
I'm going to get to that. I'll get to why I think they're important in a moment.

Michael Manville 18:44
And I mean, it's not so much that you're undercutting it. I think you're, I guess one way to put it is that in the situation that a lot of cities are in, the causal mechanism is very important, but a lot of progress could also be made just working within a framework of we have a lot of unsatisfied preferences. But both matter. Yeah. And I think that one reason Adam's research becomes important is because, and of course I'll let him explain why he thinks it's important too, but one reason that I think it's important is that when we start talking about the causal relationship, one of the big questions that comes up is sort of like, well, how much causality occurs on the margin, right? As we slowly change a neighborhood, as we slowly change the kind of environment people are in, because most people, if you just kind of explain it to them at an extreme, they understand. You talk to someone who lives in Iowa and they took a vacation with their family in Manhattan. Well, the built environment turns them into a walker, right? They probably don't even think about it, but if you ask them, you just say, well, why didn't you rent a car when you got there? And they'd be like, oh my God, there's a stop sign every hundred feet, the parking costs a fortune, the traffic's awful, it's just so much easier to walk. It's like, okay, well, there you go. Like in every other aspect of your life, you drive everywhere, we drop you in Manhattan, you walk. But then I think the question that that person would have, and that we sort of have as researchers is, well, Manhattan's kind of far out there on the spectrum, you know, how much do we have to change the typical American environment before we start to see some of these behavioral changes? And that's where I think causal research of the kind Adam does starts to really shed some light.

Adam Millard-Ball 20:23
Yeah, and I think that difference between the marginal changes and the larger changes are really important because certainly the market is telling us right now that there's a shortage of walkable places with less parking, but it's so expensive to live anywhere close to transit. And I think that I don't want to sound like an old grump and say, like planners today have it so easy. But when I was starting out in my planning career, like there was a lot of anguish about like how to get developers interested in providing like products with less parking and close to transit. And like how to give developers the right incentive so anyone would even like give you the time of day. And now it's pushing against an open door. So the developers wanting to provide it, people wanting to live in these types of places. And the obstacle is really cities and zoning codes and other requirements. So it's pushing against an open open door. Then what I think the causality is, is important to demonstrate is that, well, what happens when we run out of people who kind of want to live in center cities? Like, is there something that can move the needle by 1% or 2%? Or can we end this in something like a five or 10 or larger percent increase if we start kind of running out of the transit geeks and kind of the no car advocates, and people who ready market for this type of product right now. And then also, I think, just diffusing, whether or not you think it's justified, like defusing the arguments of those people who just will say, well, self selection, and can discount the research, whether that's academically, but also among practitioners. I think that has infused them as well, that kind of maybe being much more skeptical than they should about some of the findings of the land use transportation literature, and especially about parking. And I see this all the time that, well, people are still going to drive. That's like the number one research. You build this with parking. People are still going to own cars. People want to own cars. It's not going to change them. The study shows that, yes, it does.

Shane Phillips 22:30
Yeah, that's really helpful. So we've got a lot of evidence that living in a place with better public transit or less parking is associated with more transit use and less driving. But as we've said, the evidence for a causal relationship is much weaker because of the selection bias problem. In our last episode, we talked with Beth Shin about a randomized controlled trial of different interventions to address family homelessness. And in an ideal world, you could do the same thing here, sort of randomly assigning people to different built environments and seeing how their transportation choices differ based on the type of place they live in. Tell us, I think this is kind of obvious, but tell us why an RCT isn't realistic here and how you took advantage of San Francisco's affordable housing lottery program to get around that problem.

Adam Millard-Ball 23:18
So certainly randomized controlled trials, that would be the gold standard for any scientific or social scientific quantitative research. That's how we know that COVID vaccines work, for example. And so while the medical and physical sciences have been really the domain until recently of randomized controlled trials, increasingly social scientists are using them as well. And there's some things that you can randomly assign in a straightforward way. Voter outreach is a good example. You can go and knock on some people's doors and you give them a message and you don't knock on other people's doors and then you see which people turn out to vote. But most of the time, much to my chagrin, it's not ethical or practical or usually neither to do this. And in particular with housing research, you can't ethically or practically assign people randomly to homes or to workplaces.

Michael Manville 24:16
Or not without great difficulty.

Adam Millard-Ball 24:20
Right, not without great difficulty. Whereas this is one of the few instances where lotteries are not just feasible, but they're also ethical. If you have a scarce public resource, how do you manage that? Well, you could do a waiting list or you, and there's many housing waiting lists in this country and abroad, or you could do a lottery. And so that's what we took advantage of in this study, that San Francisco's affordable housing program, it has immense demand for below market rate housing in San Francisco. And so the program, even as it's scaled up, can only satisfy a small proportion of its applicants. So this lottery, while it's not technically randomly assigning people to buildings, it's doing it as good as random. So it's a natural experiment, which isn't randomized, but in practice, it's as good as random assignment. And that's because it's the research upside of a really sad situation that housing is so expensive and that there is so much demand for this housing. So across all the lotteries, it was just over 1% success rate. So just over 1% of applicants for each individual lottery were successful. And some of these border on the absurd, like there's you have a situation with 95 units being essentially raffled off and there's more than six and a half thousand applicants for those 95 units. And so that means that people can't be that picky if they want housing. And so, but if you win one of these lotteries, then you're really unlikely to say, well, you know, I want to wait for the one with parking or I want to wait for the one with transit because it's really unlikely that you're going to win that lottery twice.

Shane Phillips 26:09
And that's sort of the different treatment groups here is you have some buildings that have no parking at all and are in places with really good transit. Other buildings that have a moderate amount of parking, maybe half a space per unit or a quarter of a space per unit and others that might have one or more spaces per unit. And people are being, as you say, as good as randomly assigned to these different buildings within the city.

Adam Millard-Ball 26:33
Exactly. People are being randomly assigned effectively to neighborhoods with different walkability, with different transit and to buildings with different amounts of parking. And really it shows that even though it took a while to filter through to the housing stock, it's the impact of San Francisco's parking reforms actually made this possible where removing parking minimums allowed some developments without parking to go ahead and others that came in at half a space, three quarters of space, in some cases, one space per unit.

Shane Phillips 27:04
So your hypothesis going into this is that the built environment will influence people's transportation choices independent of their personal preferences. So if you had two people who were the same in every way and you assigned one to a building with no parking in a neighborhood with great transit and the second person to a building with lots of parking in a neighborhood with bad transit, the first person would use transit more and they would drive less than the second one. What did you actually measure to test out that hypothesis and what did you find ultimately?

Adam Millard-Ball 27:35
So the nice thing about both randomized experiments but also natural experiments like this is that once you have this natural experiment, the research process is actually much simpler than in most cases. So we just simply did a survey of the residents of these buildings and we were working with the San Francisco Mayor's Office of Housing and Community Development and they were great partners and we couldn't have done it without their buy-in and cooperation. And so we sent people postcards where we had email addresses, we sent them a link to an online survey in four languages and so we asked people about like how many cars they own, how they get around, how they commute to work and also about their employment. So we tried to keep the survey really simple so that we wanted more responses even at the expense of less complex surveys. And so we got nearly 30% response rate which is beyond what I was hoping for expected from this type of survey.

Shane Phillips 28:37
Yeah, it's great. So what was the effect and sort of how big was the effect based on transit quality and the amount of parking in these buildings?

Adam Millard-Ball 28:45
So there's an effect. So that was the first order of business. It was measurable. Yeah. And which to the self-selection crowd might not have been quite as obvious and especially for the parking self-selection crowd might not have been as obvious. And that moving someone from a less walkable to a walkable neighborhood or from a building with parking to one without parking, it changes how they commute, how they travel for other trips and how many cars they own. And so yeah, you might say that's not surprising, but the people who think that the whole effect of the built environment is because of self-selection, that hopefully goes some way to convincing them that self-selection is not a whole story. And then in terms of the, is this a big effect? Well, it depends on what you think is big, but it's certainly measurable and I think it's substantively important that say, if you move someone from the transit accessibility as the outer sunset, that's a really suburban neighborhoods with lots of parking, not great transit. In San Francisco to Potrero Hill, which is an inner suburb, one of the kind of denser inner rings. And that's actually the citywide median. There's a 6.5% increase in transit mode share rather than car. Yeah, that's pretty big. That's a big effect. And not even from one extreme to another, from a pretty car dependent neighborhood, but there's still some transit to one that's just at the median of the city.

Shane Phillips 30:20
And you were actually looking at the metric of transit quality on the one hand, transit quality accessibility, whatever you want to call it, and then parking in the building on the other. And obviously those combine in some sense, but correct me if I'm wrong, but the impact of having less parking in your building was greater. So it increased transit ridership more than improving the quality of the transit actually.

Adam Millard-Ball 30:44
Absolutely. And that was perhaps the biggest unexpected finding for me was just how dramatic that comparison was, that parking mattered more than twice as much as transit in determining whether people take transit or drive. And so that these sticks in terms of like making car use less subsidized and have a bigger impact than making transit frequency and accessibility better.

Shane Phillips 31:13
Yeah, and I think it's worth emphasizing that that's a pretty consistent finding with previous research that actually making it harder to drive, including harder to park, seems to have a greater impact on the way that people get around than improving the quality of transit does, which is a little, I don't know, kind of disappointing in a way, but I think that's pretty consistent. Mike, maybe you have some other examples you can point to of that. I'm thinking of like the parking cash out, which is sort of an example of that, but I know there's others.

Michael Manville 31:43
Yeah, there was a great paper maybe seven or eight years ago that Dan Chapman at UC Berkeley wrote about transit oriented developments that the title was, does Todd need the T? Which basically said that actually if you just had a kind of a dense walkable neighborhood, it almost didn't matter if there was, in his example, a rail station there, because you would actually see more walking and more moving around outside of a car and less vehicle miles traveled just because of that built environment. And I think it might be, I guess it could be interpreted as being sort of discouraging if you're a transit junkie, but if you're just someone who is interested in different ways of moving around, it's quite encouraging just because a lot of transit is very expensive. And it suggests that there's a lot to be done and there's a lot that can be accomplished just by getting people to sort of implicitly rethink their choices short of sort of reorganizing the entire neighborhood. None of it should be interpreted, in my opinion, as an argument against more transit. But just saying like, look, a lot of us, we don't realize the extent to which the car is sort of artificially low priced for us. And we don't realize the extent to which we hop in the car when there really are other things we could be doing, even in a car oriented environment. Could I walk down the street to the store? Could I bike over to see my friend? And just changing that calculus a little bit can change travel behavior in ways that don't need to require sort of like extending the BART or something.

Shane Phillips 33:20
Yeah, and it's actually, it's funny because extending the BART, adding new bus service, these are expensive things, they're worth doing, but they do cost money. Building housing with less parking not only doesn't cost us any money, but it also saves tenants and home buyers money. So it actually costs us less than nothing.

Adam Millard-Ball 33:39
Picking up on Mike's point about cost subsidies, I think the dynamic just goes to show just how easy it is and cheap to drive by car and how hard it is to compete with that for transit. And if you are fighting or trying to compete with a mode that there's no parking costs that are charged to you, that gas is cheap, that you get priority on the road, and you don't even have to stop for pedestrians at crosswalks, then it's how, how are you going to compete with that? Like however good transit is, it's an uphill battle. And that's why I think the research shows that even really modest charges, whether like a dollar a day for workplace parking, or slight changes in car access have a much bigger effect than improving transit. Because even if we double the frequency of transit, it's still gonna be slower than taking the car in most cases.

Michael Manville 34:40
That's right. I think there's something about a price that's zero. This is why zero is a special number, right? It's a special number mathematically, you can't divide into it or whatever. But it's also, I think psychologically, if something is really priced to zero, you don't have to be at all mindful about it. And even if it is just a dollar, suddenly you think about it in a way that you didn't think about it before. And Adams, I guess we're feeding off each other here, but this point, it really is worth emphasizing about the artificial cheapness of driving. And we're going to just, the podcast is now UCLA Transportation Voices. I'll take us into it. I mean, it just, because right now in Los Angeles and in many other places, there's a lot of discussion about it in Boston as well, should we make transit free and get rid of fares? And there's good and bad arguments for that, and I won't weigh in on it other than to say that the big obstacle to transit use in the United States is not that transit is expensive, right? Because transit is already heavily subsidized. That's not to say there isn't a case for subsidizing it even more. It really is that the other alternative is so cheap and convenient, right? The big obstacle is not that it costs $1.75 to get on Metro. It's that if you have a car in Los Angeles, chances are you have free parking where you live, you have free parking where you work, you have free parking where you shop, and even if it was free, that's probably what you'd do. And so it really is sort of the relevant price that dictates the mode choice is just, it's beyond the fare box of the transit system.

Shane Phillips 36:14
Yeah. Adam, do you find it surprising how big of an impact the built environment has here? Or maybe, you know, surprising isn't the right word. I guess I find it kind of encouraging that these relatively small changes in the places that people live can lead to pretty large shifts in mode choice. And of course, all the economic and environmental and other benefits that come along with that. I feel like we're led to believe that people are pretty set in their ways and the behavior is hard to change. And I think in many cases that really is true. But maybe the reason that doesn't apply as much here is just because we're catching people when they're already sort of in the midst of a big life change, almost by definition because they're moving. As someone who spends more time thinking about transportation than I do, I'm curious to hear some of your reflections on just what this represents for the future of cities more generally, you know, meeting our climate goals, anything else in that vein.

Adam Millard-Ball 37:09
Sure. I think there's this narrative which I hear from the public, I hear from my students, I hear everywhere that Americans just are in love with their cars and they will drive regardless of anything and that Americans are special in that regard. But, you know, I've lived in the UK, I've lived in Canada, like people there kind of like their cars too. And you can make the same argument. And while there might be some people who are kind of really into the car design or something like that, I think there's a much bigger group of people who are just, they love their cars because they're usually cheaper and quicker to get where they want to go. And so, making even modest changes to the relative costs and speeds of cars compared to the alternatives, it's not surprising to me that that has impacts on travel behavior. And perhaps what I was most surprised of was the findings on how much a building's parking supply or parking ratio affects car ownership and travel because these buildings aren't banning people from having cars. But there's plenty of parking in San Francisco and other places. And there's a really healthy secondary market. You can go on Craigslist and you can rent a space for a couple of hundred dollars a month. You can park on the street if you're willing to move it every week for street cleaning and pay a token a man for a residential permit. So even these parking free buildings, they're not car free. And many of the people who lived in these parking free buildings, actually 38% of our sample, they still had a car. So it's not stopping people who need a car for various reasons or are really attached to their car from having one. It's just making it a little more difficult, a little more expensive, and a little slower because maybe rather than just riding in your building, you have to walk five minutes down the street to the space that you rented.

Michael Manville 39:07
The other thing I want to emphasize about Adam's study is that one could listen to what we've said so far and say, oh my goodness, well, but you're just studying a bunch of people who want below market rate housing. Of course, they're not going to drive that much, they're low income. And this is the tragedy of San Francisco, which is that it's so expensive that even fairly, by many standards, very affluent people can enter these lotteries. I believe the cutoff for entering an affordable housing lottery in San Francisco is over a six figure household income. And so this is not, I just want to make sure our listeners understand this, we do not have this potentially non-generalizable subsample where we're studying very low income people who need subsidized housing. And so obviously they're always looking for a way not to drive, they're naturally riding transit.

Shane Phillips 39:55
And $200 for a parking spot every month would be unattainable.

Michael Manville 39:59
A tremendous burden. I mean, there's some attorneys in this mix probably, right? And so that's important to understand.

Shane Phillips 40:07
I don't know if an attorney is taking a job for under six figures in San Francisco, though.

Michael Manville 40:11
There's some bad attorneys. Kind of bottom of the class at Berkeley. But that's a fair point. The other thing I want to say, which is it was related to Adam's point that almost 40% of the people they did study did have automobiles, is that people get surprised by these impacts. And I think that's understandable. But part of the beauty of this, and that's sort of hard to appreciate, is that you can get a lot of really meaningful changes in people's behavior without having them turn their lives upside down. I think there's sometimes in the public discourse around this, there's this idea that you're going to build a house, build an apartment, some of the housing's not going to have parking. And so for that to do any good at all, the people who move in have to just turn into freakish Earth Day people who would never get in the car. And certainly you do get a lot of bang for your buck in reducing VMT if you do tip someone who was going to own a car into not owning one. Because once you don't own a car, you really don't drive much at all. But as he was saying, if you just now live in a situation where you have to walk five minutes to get to your car, there's probably a lot of daily things that are within a five minute walk of where you're going. And so suddenly you're just not driving for that trip. And over a lot of people and a lot of time, that adds up. And what doesn't even seem like a big change to you, but it is on a neighborhood level and sort of an aggregate level, a large change in sort of how much people are driving and how much people are using their automobiles.

Shane Phillips 41:47
Yeah. And I know Adam, you probably didn't get to this level of specificity in your survey, but I imagine a lot of the residents who responded and who moved into these affordable homes, they probably moved in with their car, even if it didn't have parking provided. And it might have been sort of over time. They didn't sell it the instant they signed the lease. They might have just kind of realized over time, you know, this is inconvenient. I can get around these other ways. And, you know, two months later, six months later, maybe by then they don't have a car, but that's not how, you know, it was just a transition that made sense. It wasn't necessarily this immediate decision changing their life on the turn of a dime.

Adam Millard-Ball 42:29
We didn't get into that in the survey, but absolutely that's reasonable to expect that the first parking ticket is annoying. After the third parking ticket you get in a month, then you just want to be done with your car.

Shane Phillips 42:41
So I was pretty surprised to learn that the people assigned to the buildings with less parking who drove less on average were still just as likely to be employed full time. I think a lot of us advocates for better public transit and fewer parking mandates really fervently wish that transit was just as good at providing good access to jobs as cars are. And they certainly can be if we invest enough in it, if we get priority on the streets to buses and complement it with the right land uses. But compared to driving in just about every place in the U.S. right now, and I think this is mostly true of San Francisco even as well, it's unfortunately just not the faster option and doesn't connect you to nearly as many jobs, transit compared to driving. Our colleagues here at the Lewis Center, including our director, Evie Blumenberg, and our very own co-host here, Mike Manville, have done quite a bit of research showing how important car ownership can be for low-income households, economic prospects, and access to jobs, all the more so in a place like Los Angeles. So since you didn't find any impact on employment, why do you think that was? Is it just a matter of San Francisco having unusually good transit access compared to most other cities, or do you think there might be some other explanation here?

Adam Millard-Ball 43:57
So certainly we did the survey at a time when unemployment was really low in San Francisco in particular, but also nationally. But also I don't think that these findings are incompatible because we're studying the effect of having parking in a building, not on whether someone has a car. And as we just talked about, there's lots of other ways to have a car in a parking-free building. You can rent a space nearby, you can park on the street, and if you are in a job where you can't get there by transit or you're working night shifts, maybe a transit might not run or feel safe, then there's no reason you can't have a car. It's just a little more inconvenient, and maybe you're paying extra for that parking space compared to if you hadn't lived in a building where parking was bundled in with the rent or the sale price. So not providing parking isn't the same as everyone in the building not having cars. And again, nearly 40% of respondents who lived in buildings without parking actually did have a car, we didn't ask where they parked. But again, there's this healthy secondary market in parking in San Francisco. And it's actually a nice segue into one of my gripes with the way that cities often plan for buildings that have less parking, that they then go and say, well, there's a condition of this, you need to prohibit the residents from having a street permit, which goes against that flexibility and is entitled to that street space as much as anyone else and almost have a greater need for that to provide that flexibility. Let's say someone gets a job or has some other change in personal circumstances that mean they need to have a car, then why force this person to move just because you want to reserve the street space for someone else. So I understand why cities do that for expediency, for perhaps overcoming some local opposition, people worried about parking impacts, but from a policy and from a basic human dignity perspective, that seems really misguided to me.

Michael Manville 46:11
Adam's answer is absolutely correct. And what I would add to it is that Adam has shown that if you put some people in particular environments, some of them might realize they can do without a car. And I think another way to think about why that's compatible with Evie Blumenberg's work, Mike Smart's work, some work I've done with Mike and Evie and Dave King is that right now in the US, if you see someone outside of New York City or San Francisco that doesn't have an automobile, I mean, there's a good chance they're a very low income person or they have some sort of medical condition that prevents them from operating a car and they suffer low mobility as a result of that. So right now, if you see someone who doesn't have a car, chances are they could use one. But the other side of that is that right now there are lots of people who have a car that they could probably do without. So I have an example. I own an automobile. It's fully paid off. I have a department building in West Hollywood with bundled parking. So if I got rid of it, I would save nothing on my rent. And I use it sometimes. I like to go hiking. I take my dog places. I like to go skiing. And so I have this car, right? But if I gave it up, I would not lose my job. I would not see my income reduced. I would suffer some minor inconvenience, right? And so the reason these two, and I think it's important, right? There's a lot of people in the United States who have a car they don't need. There's an even larger number of people who have a car and use it more than they have to. And that's a different problem than that there's actually a pretty small proportion of people in the United States who don't have an automobile and whose life would be changed if they had one. But the way to help those people is to identify them and get them some help, not to look out over the vast expanse of America's built environment and mandate parking, right? That's a very inefficient way to help a very small number of people who really do need some direct assistance.

Shane Phillips 48:15
Yeah, among other things, they need the car, not the parking. Yes, right. So as we wrap up here, is there anything we missed in the paper that you wanted to cover? Any key points here?

Adam Millard-Ball 48:28
The big point that I'd want to emphasize and that you touched on the start is that there are 20 really good reasons to create more walkable neighborhoods and provide choices in how much parking both residents and developers have to have. And while I think that the travel behavior side is really important, I think that work of Don Shoup and Mike Manville and many others has shown that there's really no good reason to have parking requirements, even if there were no travel behavior impacts. So in many ways, this is just kind of a bit of a pylon and not beating a dead horse because a horse is still really much alive and kicking for some strange reason. We already had enough evidence for why parking requirements are a bad idea, but perhaps it's going to be one more study that just pushes at the margin. But parking policy is a great way to address issues of traffic and transportation. But we shouldn't forget that it's also a really important way to address issues of housing affordability as well.

Shane Phillips 49:41
Adam Millard-Ball, thank you so much for being on the show.

Michael Manville 49:44
Thank you. Yeah, thanks. It's been great.

Shane Phillips 49:52
You can read more about Professor Millard-Ball's research and find our show notes and a transcript of the interview at our website, lewis.ucla.edu. The UCLA Lewis Center is on Facebook and Twitter. I'm on Twitter at Shane D. Phillips and Mike is at MichaelManville6. Thanks for listening. We'll see you next time.