Autonomous cars in the advanced city

Robin Chase, founder of Zipcar, said this to Yonah Freemark last month:

Would you prefer what we have today, [where] only poor people use [most transit service] and it sucks, or would you rather that poor people use the exact same thing that everyone else is using?

This brought to mind a quote that Chase has no doubt heard from Enrique Peñalosa, the former mayor of Bogotá:

An advanced city is not one where even the poor use cars, but rather one where even the rich use public transport.

Peñalosa's quote highlights the false dichotomy that Chase has set up: there are other ways to provide access for poor people besides (a) sucky transit and (b) the exact same thing that everyone else is using. (And really, Chase ought to know that everyone else won't use "the exact same thing." How long did Zipcar offer a single model of vehicle?) As Yonah points out, there are also other options for the non-poor besides autonomous cars that only hold a few people at a time.

Both Chase and Peñalosa make other good points, and both are wrong on other points, but on this point the Strong Towns movement has gathered abundant evidence to back Peñalosa's position. We simply cannot afford to have an advanced city, let alone an advanced society, if we are spending our resources moving so many single individuals long distances at high speeds.

Could we build another Park Slope?

Do you like the modern towers of the Upper East Side?

Photo: Peter Cigliano / Flickr.

How about a nice gigantic Upper West Side prewar apartment building like the Ansonia?

Photo: wallyg / Flickr.

Or the brownstones of Park Slope?

Photo: Beyond My Ken / Wikipedia.

Or is all that too dense and urban for you? Maybe you'd prefer the lovely Victorians of Irvington, NY?

Photo: June Marie / Flickr.

Gorgeous places to live! Of course, you and I are not the only ones who think so. These are some of the most desirable locations in the country. There are millions of people who would love to live in places like these.

So why don't we build more?

Why not buy up a block of crappy 1960s Stately Homes in Woodside and replicate the Ansonia? Or raze some raised ranches in Massapequa and build a block of brownstones? Build a new Victorian main street leading down to the Croton station, where now there are strip malls?

It turns out that there are some attempts to do this. Andres Duany is involved in a project in Jersey City that looks pretty cool. If you know of any others in the New York area, please let me know!

Unfortunately, those projects are a drop in the bucket. Zoning rules across the region make it next to impossible to build big modern towers on the Upper West Side, or a new Ansonia in Park Slope, or a block of brownstones in Irvington, or a new Irvington in Scarborough. The Municipal Art Society's recently released zoning envelope map confirms that the massive downzoning conducted across the city by Mayor Bloomberg and Commissioner Burden reinforced this prohibition. And people wonder why rents keep going up...

New transit and our goals

It's pretty much a no-brainer that anything that optimizes existing transit use will help us toward our goals. Getting people out of cars and onto existing bus runs, or out of buses and onto existing train runs, means less wasted resources, less pollution, less carnage and more transit riding voters. And as Eric Morris has pointed out, the other extreme is true: a hugely expensive, physically disruptive transit project that gets a few people out of their cars for a short period of time but continues to encourage sprawl development and driving is something that we're probably better off without.

The question then becomes: where do you draw the line? Which designs and configurations should we always say no to? If you have a limited pool of money, how do you decide between two new transit projects? First of all, we shouldn't back any project with a competing highway project. Beyond that, we can start with Alon Levy's "trip chaining" principles that I discussed in my "Carfree 24/7" post:

		Short trips
		Foot or bicycle	Car
Long trips	Transit	Transit/walkable	Commuter suburbs
	Car	Auto-oriented dense	Sprawl

When we talk about getting people out of their cars, the goal should be to get them completely out of their cars. That means transit for long trips and walking (or cycling) for short trips. Transit without walkability means that people will be driving to the store and to drop their kids off at school. Walkability without transit means that people will be driving to work, major shopping and vacations.

Transit and walkability also reinforce each other, just as local and long-distance car dependence reinforce each other. Walkability solves the "last mile" problem for transit, and people in cars tend to stay in cars.

This means that the projects with the biggest bang for the buck are ones where there is walkability without transit, or transit without walkability. We build the transit to serve the walkable community, or upzone around the transit station, to bring the transit and walkability into balance.

The next most desirable transit projects are those that build transit and walkability together. I'm often skeptical of these, especially when they're greenfield developments, and that's another principle: infill is better than greenfield, all else being equal.

We can rule out projects that are neither walkable nor transit-oriented, but simply promote 24/7 car dependence. But what about sprawl transit proposals, like the Northern Branch, the Tappan Zee transit and extensions of Metro-North, which are at best accompanied by vague promises of rezoning? What about proposals for dense, walkable villages in locations underserved by transit, if they are served at all, like the Piermont pier and the Piscataquis Village Project?

In general I would say no to projects like these. If we wait a generation, people will probably be more open to transit and walkability, and we don't want to get locked into highways, garages and single-family sprawl. But there are circumstances where they might make sense. Sometimes you need to move fast to lock down a right-of-way. Sometimes you need to spend money on transit before the road people grab it.

There's an argument that's frequently made that park-and-ride transit can function as a ratchet. Get people on transit for a little while and they'll identify as transit riders and support transit expansion. Get people walking a little and they'll demand transit. I'm not convinced. I know too many transit-riding car owners who identify as drivers first and foremost, and vote that identification. If there was some kind of explicit time limit, where termites would gradually eat the park-and-ride or something, I might consider it.

In any case, these "maybe" proposals should be lower priorities than the other ones, in terms of land, money and activist time. So to sum up:

Yes!	Maybe!	No!
Use existing capacity Build transit to serve existing walkable communities Upzone existing transit-oriented communities Infill transit and walkability	Greenfield transit and walkability Lock down an existing right of way Spend money while it's there Sunsets	Anything with a competing highway investment Park-and-rides Transit-inaccessible walkable villages Ratchet arguments Autosprawl

Buses and trains in Woodhaven

In this blog, Capt. Subway has written that we should run the R subway on the unused Rockaway Beach Branch of the Long Island Railroad, and I've written that we should run Select Bus Service on the parallel Woodhaven Boulevard.



On one of my followup posts, BBnet3000 argued that the Rockaway Branch is not well enough located:

Also, most of the commercial development in this area is along Woodhaven Boulevard, which this subway kind of misses. Theres a reason subways are usually built under streets. When I ride the bus on Woodhaven Boulevard (to go to the auto-oriented Trader Joes incidentally, though Forest Park is also worth visiting) I usually think id like a better bus, rather than a train a block to the east (for what its worth, this bus seems to have pretty good ridership, and a lot of people DO ride it to the Rockaways in the summer). For the densest parts of Woodhaven its several blocks to the east and inaccessible through the private properties of the Rego crescent.

There is in fact walkable commercial development along that section of Woodhaven Boulevard from 62nd Drive to where the cemetery starts at Furmanville Road, but that's the only walkable commercial development the entire length of the boulevard. North of 62nd Drive you've got an apartment complex, a Catholic school parking lot, a deli and a park before you get to Queens Boulevard and the subway station. South of Furmanville Road you have the cemetery on one side and sprawly stores on the other, then the big-box stores, then the Montauk Branch.

South of the Montauk Branch there are a few businesses, but they are almost all located on street corners. The vast majority of commercial use in this corridor is on the avenues that cross it: Metropolitan, Myrtle, Jamaica, Atlantic, 101st and Liberty Avenues. On Woodhaven itself you see mostly houses - and a lot of one-car garages.



If you walk down one of those avenues, the Rockaway Branch is never far away.



One thing to remember is that this is not just about better access to existing businesses, but enticing more and better businesses to locate there. The commercial buildings along the avenues are generally two stories, allowing for greater walkability - more shops, restaurants and offices in a small area. The ones on Woodhaven Boulevard are mostly one story, which limits their potential.

So yes, Select Bus Service would be good for the commercial stretch of Woodhaven north of Saint John's Cemetery, but a subway would be better for businesses further south in that corridor. That's why we should have both.

The Island of Sausage Heros

Last week I was walking down Woodhaven Boulevard along Saint John's Cemetery, and I came across a food truck selling Italian sausage heros.

Google Maps tells me that this is on the edge of Middle Village, but it's kind of Forest Hills and kind of Rego Park and maybe a little Glendale. In any case, there were a lot of guys (yes, all guys, mostly working class guys like plumbers) getting heros. I got one. It was good.

It's only now that I discover that D'Angelo's Sausage and Pepper Truck is actually pretty famous, serving those heros from the same spot for forty-three years. Victor Mimoni called it "The Peter Luger's of Sausage Wagons." I saw a hot dog truck a block north, and it's owned by the same family. D'Angelo's sausage was named one of the Best of New York by the Daily News in December.

The odd thing about it was that there was nowhere for me to eat my hero. It would have been really messy to eat standing up, but there were no benches. There was a bus stop a couple of blocks away, but it was only local buses, and nobody had used it. The trucks weren't all that close to the cemetery gates, and none of the guys went inside. Instead they walked to their cars and sat inside and ate. I was the only one who had arrived on foot.

I didn't have a car to sit in, so I kept walking. Eventually I came to a little triangle park and ate there, but I've been thinking about this place ever since. There is always a space for the D'Angelos to park their trucks. As you can see in the picture, there is no standing allowed overnight. I'm so used to people complaining about not being able to park that at first I was surprised to see so many spaces empty. Then I realized that these spaces are a long walk from anywhere.

This side of Saint John's cemetery is a half mile long. Woodhaven Boulevard is ten lanes wide here, and there is only one crosswalk in the whole stretch. There's really nothing much interesting on the east side of the boulevard in this section either: a bunch of gas stations and car washes, and single-family houses behind them. In other words, only a handful of people live or work within walking distance. Hence, nobody cares if the parking spaces sit empty all night, and all of D'Angelo's customers drive.

It all adds up to a strange little island off the coast of the cemetery, a place that nobody walks to. People drive there, walk to the sausage truck, eat in their cars and drive away.

The density to support long distance trains

There's a new dust-up among transit bloggers, stirred by a recent report showing that while Amtrak's Northeast Corridor makes a profit and the state-sponsored corridor trains break even, the long distance trains are still losing money (although Don Phillips disputes those numbers). Eric Jaffe gives three arguments in favor of keeping the subsidies for the long distance trains, while Jarrett Walker and Bruce Nourish make an austerity case for dropping them. Paul Druce won't go that far, but argues that we should at least charge market clearing prices for berths in the sleeping cars.

"Overnight Train to Beijing." Jay Dedman / Flickr.

Here's the key quote from Jarrett's comment on Jaffe's post: "Rail is optimal for particular distances. Europe has lots of great rail services, but still, if you’re going 2000 miles within Europe, and you’re not a tourist or time-rich wanderer, you’re definitely going to fly. ... Australia is too big for rail networks to be national, and so are the US and Canada."

I've faulted Jarrett in the past for transportation myopia, and here it's causing him to repeat the old "density to support transit" canard. These are the three questions that get you out of this myopic viewpoint:

1. Would transit work if it had a better mode share?
2. Does the area have the density to support roads or airplanes either?
3. Would people live or work more densely if the car or air infrastructure were less subsidized?

1. Would long distance trains work if they had a better mode share? Absolutely. Take the ridership on just about any Amtrak long distance route and there are more than a hundred times that many people driving or flying. Shift half of those drivers or flyers to the train, and you can charge enough to break even.

2. Does the area have the density to support roads or airplanes either? No. There are very few highways that pay for themselves, and I don't think any of those compete with trains. Air service is heavily subsidized: public airports, publicly funded air traffic control, Essential Air Service.

3. Would people live or work more densely if the car or air infrastructure were less subsidized? Yeah. You'd still have people living in Seattle and Phoenix and along train lines connecting them, but a lot less in small towns scattered around the country.

So we see that it's not that Australia, the US and Canada are too big for national rail networks. It's that they're too big for three national networks, road, rail and air. Cut the subsidies to one of the other two, and we can get enough passengers for rail.

Jarrett makes a further argument based on efficiency with his remark about the "time-rich wanderer," which is echoed by Nourish. That may have merit, but it's a separate issue, and it doesn't help anyone if you conflate them. I'll deal with it in another post.

The benefits of density come from less space for cars

There's been a lot of good talk about density lately. Last week I pointed out that a lot of what some people object to about "density" is actually less space for their cars. The flip side to this is that a lot of what we want from "density" is actually less space for cars. Let's go back to our goals (see above):

Who needs a condo in Hackensack?

Reducing pollution and increasing efficiency: Density can mean less need to drive places, lower construction costs per unit, and more efficient utility networks and goods distribution. Surface parking and wide streets undermine all of these.

Reducing carnage: Density can mean more people walking or taking transit instead of driving, and drivers that are moving slower and paying more attention to pedestrians. Surface parking and wide streets undermine all of these factors.

Improving society: Density can mean enough "eyes on the street" to make it really safe without the need for intensive policing. It can also facilitate more face-to-face contact with neighbors, and more chances for small positive interactions. As Eric Fischer pointed out in the comments to my previous post, Donald Appleyard documented the negative effects of wide streets with fast-moving cars on social networks. Parking lots are almost always unpleasant to walk through, let alone across.

Access for all: Density can mean a more efficient transit network, with higher ridership and thus less need for government subsidies. Spreading out transit destinations with roads and parking lots make transit less efficient and less desirable. The more money you put into a parallel road and parking network, the more you undermine transit ridership.

The thing is that you can have all these problems with high density. Multi-storey parking undermines construction savings and utility network efficiency. Making it easy to drive undermines any effort to reduce pollution and carnage or to save energy or increase transit ridership. The street level facades of multi-storey parking, can also make life unpleasant for people in the area.

How much of "density" is just less space for cars?

There are many benefits from living and working in dense environments, but there are plenty of people who are against density, and come out in large numbers to protest any large development or increase in zoning allowances. Today, for example, David Alpert at Greater Greater Washington wrote about a full-on NIMBY freakout over small houses in alleys. Often this is couched in some half-baked argument about "quality of life" or "preserving the character of the neighborhood." As I wrote before, it's worth listening to NIMBYs, but NIMBYs are people, which means that you can't take everything they say at face value.

ADU with finger. Photo: Linda Schmitt via Greater Greater Washington.

When I first heard phrases like "quality of life" and "the character of the neighborhood" I had no idea what they meant. I couldn't understand why Rudy Giuliani claimed to care about quality-of-life issues, but didn't seem to care that hot dogs come in packages of ten while hot dog buns come in packages of eight.

I got a lot of help understanding the anti-density mentality from StongTowns's Ian Rasmussen, who laid out his "party analogy" in this podcast with Chuck Marohn. Ian points out that at some parties, the guests bring more than their share of alcohol (and food, I would add), so every guest increases the fun.

In recent years, however, urban development has been more like a bad party full of stingy guests who don't even bring enough alcohol for themselves. "Every time someone shows up at the party, the party gets worse," Ian says. In the experience of residents, "Virtually every time a shovel went in the ground in the last fifty years, things got a little worse."

How did things get worse? Kaid Benfield talks a lot about access to "nature," and how often "dense" developments reduce the amount of parkland per capita. Others have talked about similar competition for resources like schools. While schools and parks are definitely important, I'm not convinced that they're the primary motivators for most NIMBYs. I think racial and social prejudice is definitely a factor for some people, but I'm not going to go into that in this post.

Ian Rasmussen paints a picture of the first arrivals at a new suburban development who are "fifteen minutes to downtown, fifteen minutes to the lake." But as more people arrive, congestion increases on the roads, and our suburbanites are now "more removed from the nearest pasture because there's another ring" of development beyond theirs. Both Benfield and Rasmussen point to congestion as a big factor. Others talk about competition for parking.

I'm leaning more and more towards the idea that in a lot of cases "density" just means less space for cars. A comment from "Bob" on Alpert's post lays it all out:

So, if these dwelling units become matter of right and are located where garages usually are, where will new residents park their cars? More vehciles flooding onto the streets? I know a family in AU Park that has a sub rosa 2 story ADU on an alley with several adults living in it. (Looks a lot like the photo, actually). Trash flows into the alley because there's no place to put it and the number of people living there. Plus 5 or so vehicles now squeeze onto the street in front of the house from this one property. And I thought that all ADU hipsters walk, bike or use Zipcar....

As in most cases, the threat from these cute little houses has nothing to do with parks or schools. It's about the value of allocating land for parking and driving. For David Alpert and most of the Greater Greater Washington readership, parking is a nasty scourge that separates people's homes from each other and from businesses without adding anything pleasant or interesting. For Linda Schmitt and Bob, parking is a scarce resource that is being gobbled up by the unwelcome new residents.

For the most part, "density" is an unhelpful, unenlightening way of thinking about neighborhood conflicts. Most conflicts about "density" are really conflicts about parking or road space. Try it yourself. Next time you're thinking of using the word "density" in this context, try replacing it with "competition for parking" or "competition for space on the road." I bet you'll find it clears some things up.

Why no parking should be the future of parking

Yesterday, Eric Jaffe of the Atlantic Cities tweeted to his colleague Emily Badger, "One day we'll find something that pleases the Cap'n." They both actually do write a lot that pleases me (such as the Transit Riders' Union post and retailers don't need parking to thrive), but I reserve the right to criticize. Like now, I'm going to criticize Badger's latest post, "Car Elevators: Not Just for Rich People" (from the slug, the working title was apparently something like "Why Car Elevators Should Be the Future of Parking").

My first criticism is that if you didn't know better, you might get the impression from the post that car elevators were a new thing, at least to New York City. In fact, we've had them all my life.

Photo: *Bitch Cakes* / Flickr.

While looking for corroboration of this, I found a story from July about an attendant who drove someone's SUV into the elevator shaft in one of these garages, but the elevator wasn't there so he crashed down five stories and hit another attendant who was actually in the elevator. Fortunately, they both survived.

We also have the columnar car lifts that you see in so many Midtown parking lots:

Photo: Dan Nguyen / Flickr.

Now these are not the individual car elevators promised to rich Chelsea condo owners or Mitt Romney, and they're not the automatic garages that Badger talks about. They're run by attendants: you drop your car off and give them the keys. They go park it, and when you're ready to pick it up they get it out for you. You don't have to drive your car in the elevator or wedge it into some tiny space.

This may be a bit less efficient than the Milstein automatic garages, but probably not much so. They're certainly a better use of space than the garages with lots of ramps that Badger compares to the automatic garages. But while elevator garages may not be just for the super-rich, I don't know who Badger thinks can afford to pay fifty dollars a day to store a car in the city, or even twenty-five. In my book, that's just for the rich.

The rest of Badger's argument - that "cars and people live in a constant competition for space," and that these automatic garages can help relieve that tension - doesn't hold up. First of all, cars don't live, outside of cartoon movies. The competition for space is between the small minority who want to drive and park their cars in the city, and everyone else who's just walking here. When minimum parking requirements don't apply, off-street space is allocated by supply and demand. If a developer can get more money from an apartment building than a parking lot, then you'll see that parking lot replaced by apartments. Making it easier for a few rich people to store their cars on top of each other isn't going to free up more space for walking and apartments. At best, it'll free up some more garage space so that the next income bracket can buy cars. Yay.

As Brooklyn Spoke wrote in the comments, unless the cars are entirely symbolic (in which case they're hugely inefficient symbols to keep in a city), people will need to transport them to and from these automatic garages on a regular basis. That means more cars on the streets, which means more pollution and carnage, and less space for pedestrians and transit. The main reason why dense cities are more efficient and less polluting is because people don't have to drive as much. If there are people who won't live in the city unless they can drive, then let them go bankrupt out in the suburbs. Cheering a technology that makes it easier for people to drive in dense cities is missing the point.

Car elevators are the past of parking, and the present. They may also be the future. But that's really nothing to applaud or get too excited about. With any luck, the future of parking will be that there's a whole lot less of it around, regardless of whether it's organized vertically or horizontally. And that's why any new parking should be convertible to other uses when the demand goes away. That's what the future of parking should be.

Gay men, zoning and the High Line's real source of power

You probably already know how annoyed I get by all the people who want "our very own High Line" for whatever little town they live in. As I wrote last year, "If you've got anyone like that in your town, you should print them out a copy of Witold Rybczinski's excellent discussion of the economics of the High Line, and why it probably won't turn your run-down industrial neighborhood into West Chelsea unless you've got (a) dense commercial and residential development nearby, (b) a subway two blocks away, (c) lots of well-connected gay men and artists living and working within a short walk, and (d) LOTS of money, more than your town can really afford to spend."

I'll add two data points to the ones from last year:

Photo: Professor Bop / Flickr

First, some documentation of the gay fundraising network that bankrolled Friends of the High Line. Here in New York we've got gay men with power and money! Is your town willing to give that much clout to its gay men? Think you can do it without them? Good luck!

Second, since 1982 there have been no minimum parking requirements in Manhattan south of 96th Street. In 2005 the city approved the Special West Chelsea District (PDF) zoning amendment. It did not add any minimum parking requirements. Would developers building around your "High Line" wannabe have to provide lots of parking?

The zoning amendment also capped any density limitations at a floor-area ratio (FAR) of 5.0. Does your town allow that much density around its "High Line"?

If anything, the High Line is a symbol. It's a symbol of a town that gives power to gay men walking among tall buildings, instead of wasting all its land and money on highways and parking lots. It's a symbol of a metropolis.

If your town doesn't do that, it's not a metropolis, and any "High Line" you build will be an empty symbol. And yes, that goes for you, Rego Park.

(I know, we still have too many highways and parking lots, even in Chelsea. The sooner we get rid of them, the better off we'll be.)

What is New York's Forest Hill?

As you may remember, Feargus O'Sullivan recently moved within London, from the "urban" neighborhood Shoreditch (I think) to the "suburban" neighborhood of Forest Hill. Many people were struck by his use of the word "suburban" to describe Forest Hill. Some ascribed this difference to British English, which he accepted, but I think that's (as we say) a crock, because even within the US or the UK, we can't keep our own definitions of "suburban" neighborhoods straight. I was also struck by his contention that every "urban" neighborhood in London is gentrifying, unless it was always wealthy. But I'm trying to find neighborhoods here in the New York area that would correspond, even roughly, to the ones he discusses.

The Railway Telegraph pub, Forest Hill, Lewisham. Photo: Ewan-M / Flickr

In the comments, Benjamin Himric pins Feargus down to the following "independent variables" (my terminology) for distinguishing urban and suburban:

URBAN
- relatively high density
- mixed use district (i.e., not overwhelmingly residential)
- close to the city core (presumably this refers particularly to areas that are not themselves mixed use)

SUBURBAN (in the British as opposed to American sense)
- relatively low density
- overwhelmingly residential
- relatively far from urban core

So can we put numbers on these criteria? Let's take a look at the London Borough Profiles, using the boroughs of Hackney and Lewisham as proxies for their neighborhoods of Shoreditch and Forest Hill:

Shoreditch/Hackney:
1.7 miles to London Bridge Station
13 minutes by transit (London Overground)
163 people per non-greenspace hectare (66 per acre)
Jobs density, 2010: 0.66
Median house price, 2010: £292,500 ( $461,857.50; PPP $351,011.70)
Gross annual pay, 2011: £32,000 ( $50,528.00; PPP $38,401.28)

Forest Hill/Lewisham:
5.7 miles to London Bridge Station
30 minutes by transit (Southern Railways)
101 people per non-greenspace hectare (41 per acre)
Jobs density, 2010: 0.39
Median house price, 2010: £235,000 ( $371,065.00; PPP $282,009.40)
Gross annual pay, 2011: £29,000 ( $45,791.00; PPP $34,801.16)

I added in some dependent variables, using the OECD's purchasing power parity multiplier of 0.76 to convert the British prices and wages into something meaningful here. We can get a map of New York neighborhoods and their densities from the Department of City Planning. Quiggyt4 on Flickr has a map of jobs density. The New York Times has a map of income, and Trulia has housing price maps.

Looking at our dependent variables of density, mixed use and distance from the city core, there are only three New York neighborhoods that have 50-74 people per acre and are less than fifteen minutes from one of the two job centers: Fort Greene, Williamsburg and Woodside. Of the three, Fort Greene is the only one that's really mixed use, meaning that they have jobs that aren't just there to serve nearby residents, and that's only if you add in part of Downtown Brooklyn. It also has the right income mix and the projects to be the Shoreditch of New York City.

So what's Forest Hill for New York City? Sadly, it's not Forest Hills, which is much too dense (63 people per acre). More likely, within the half hour limit if you take the railroad, are Greenpoint, South Jamaica, East Flushing and Hollis. They're significantly more residential than Fort Greene or Williamsburg. Greenpoint is probably the best candidate for an analogue to Forest Hill.

Interestingly, of course, Greenpoint is the one New York neighborhood that Feargus mentions, and it's in his list of "currently hip city neighborhoods anywhere." I guess that just shows that "suburbs" - of any kind, really - aren't immune to gentrification. People got priced out of Williamsburg and they went to Greenpoint.

Another thing I noticed is that I couldn't find any neighborhood that had incomes and prices comparable to those in London, at similar densities. As you can see on the New York Times map, income levels in New York form a donut; once you get past the Van Wyck Expressway, or Van Cortlandt Park, or the Watchung Mountains, income levels rise the further you get from the city. There may be some cheap, low-density neighborhoods in New Jersey; I'll check that later.

I have read similar "Why I moved to the suburbs" stories that take place in the New York area, but the commutes tend to be significantly longer and the housing quite a lot more expensive. It's interesting that in London, the suburbs are still a bargain.

Fearmongering

I was really annoyed by Elizabeth Rosenthal's article in the Sunday Times, which led with this sentence: "In a quarter-century, at the rate Nigeria is growing, 300 million people — a population about as big as that of the present-day United States — will live in a country roughly the size of Arizona, New Mexico and Nevada." OMG! Can you imagine! I have visions of everyone from New York City crowded into Area 51, the population of Los Angeles stuffed into the Gila Wilderness, and the residents of New Jersey overflowing the Grand Canyon.

Nigeria's land area is 351,649 square miles. The current population is 162,471,000 for a density of 462 per square mile. If the country hits the 300,000,000 people total that Rosenthal suggests, it would have 853 people per square mile. That's a big jump, but today there are 39 countries that are denser than that. Okay, some of them are urban microstates like Macao and Monaco, or poor countries like Bangladesh and the Philippines, but there are other quite respectable First World countries where people lead a decent lifestyle and even have quiet places to go outdoors. How upset would we be if Nigeria turned into South Korea, Israel or Belgium?

To her credit, Rosenthal does acknowledge that birthrates and even populations have been declining in many countries around the world, and that the birthrate is even declining in Nigeria itself, but that seems only a small obstacle on her rush to sound the alarm. She makes no mention of the fact that there are tens of millions of people living comfortably in denser countries, and in denser areas of low-density countries like the United States and Canada.

There's even a correction to Rosenthal's article, stating that she originally said that Nigeria was only the size of New Mexico and Arizona. The fact that she chose two (and later three) of the emptiest states in the country is telling. In fairness, the biggest states are the emptiest, and to find some that add up to 352,000 square miles with higher density would require more than the magic two or three. But choosing Arizona and New Mexico creates an unnecessary contrast that can distort the emotional impact.

The bottom line is that population density isn't always bad. Whether it's good, bad or indifferent depends on how much of the land's resources are being used up. For Nigeria, Rosenthal doesn't give us much detail.

Fearmongering may seem like a good idea at the time, but it can easily backfire and put an entire campaign in jeopardy. It's dishonest, and it's too much trouble.

Three factors in density

I concede defeat on one aspect of the density thought experiment: the commenters convinced me that there are places that don't have "the density to support transit" even if everyone who wants to go anywhere takes the transit. Phelan, California and Fort McMurray, Alberta may be examples of this. However, there are three aspects of the story that I'm sticking to:

1. If these places can't support transit, most of them probably can't support roads either. That's "support" either in the sense of inducing enough tax revenue to pay for their construction and maintenance, or providing a public service that would be considered worth the investment.

2. Most of the places that are generally claimed to "not have the density to support transit" are of the kind that would have the density to support transit if it had a 100% mode share.

Image: Transit Nerds (Jeff Wood) / Flickr

3. As Jonathan said, if you make driving expensive or unpleasant enough (or if you just don't bother to make it cheap and comfortable), people will move to places where they can access things easily through walking and transit. That's the transportation-land use cycle that I identified in 2008 (here seen in a cleaned-up version by Pantagraph Trolleypole).

So the next time you're tempted to say something about "the density to support transit," ask yourself these three questions:

1. Would transit work if it had a better mode share?
2. Does the area have the density to support roads either?
3. Would people live or work more densely if the car infrastructure was less subsidized?

Density thought experiments

In recent posts, I've discussed how density isn't all that important in transit demand, how the idea of "supporting transit" is problematic, and how different people have different goals for transit, and density affects these goals differently. Because my own goals (see the top of this page) are wrapped up in a feedback loop based on mode share, my most intermediate goal is getting people out of their cars.

Transit mode share, in fact, is where density is least relevant. This may seem surprising, but only if you believe that density is the only way to control the relative value that people get from various modes. The transit boosters who worry about density actually believe that it's possible in the short term to increase the value of transit by throwing more money at it, but that that's unsustainable in the long run. Their big blind spot is that we actually have quite a bit of control over the value of driving, if we can find the political will.

This brings us back to the Magic Formula for Transit Ridership:

1. Give transit its own right-of-way and good terminals
2. Make it hard to use cars
3. Make it expensive to use cars
4. Profit!

Many transit advocates have enough exposure to the concept of (3) in the form of congestion pricing and gasoline prices, but they seem very resistant to considering step (2), probably because they don't want to be accused of wanting to take anyone's car away. The Very Serious People are all afraid to talk about decreasing the size of the road network.

But what if, while Spain was building all those high-speed rail lines, they didn't also pump billions into a truly gigantic highway network? If drivers faced constant congestion on old highways, wouldn't we expect higher ridership on the trains? Wouldn't we also expect that if the highway network was old and small enough, but the train network was the size it is today, eventually there would be enough demand for the trains that they would be completely profitable - operations and capital?

You can do the same thought experiment with any place. No matter how sparsely populated it is, just subtract some roads while keeping the rail and/or bus network constant, and eventually the place "supports transit." Take Wyoming. Now imagine it without interstate highways. Would that be enough to support restored passenger service on the train lines? How about if we turn all the roads to gravel?

Back in 2010, I had a similar discussion on Human Transit about the supposed convenience of cars. A lot of people had problems with the idea that convenience was dependent on the quality of the infrastructure, but I think I showed that if you throw enough money at any transportation system you can make it feel convenient to its users.

Similarly, if you make the car infrastructure shitty enough and expensive enough, you can make transit feel like a bargain. Density may make it politically easier to support transit expansion or harder to support road expansion, but that's not a matter of "the density to support transit," it's "the density to make it likely enough that transit will receive more political support than roads," which is not the same thing at all.

If you're really not convinced, I challenge you to come up with a place, or a route, where you can't increase transit ridership by taking away roads or increasing prices. If you want data, I have density and mode share figures for all of the municipalities and census-designated places in the New York Combined Statistical Area. Go for it.

Density and our goals

On my last post I got some great comments! Jeff "Pantagraph Trolleypole" Wood pointed us to Pushkarev and Zupan suggesting that commercial density is more important than residential density back in 1977; Jeff summarized that argument in 2010. So that's where a lot of this comes from.

Richard Layman points out that some parts of the transit network can reinforce others, and that it may therefore be valuable for apparently unjustified transit routes and runs to be cross-subsidized by "popular" routes, or even by the government. Jeff also pointed to the value of high-speed rail in inducing dense development near stations, and I think if we put these together we get something that Germà Bel's analysis misses: that an "unprofitable" high-speed rail line can be worth subsidizing if it gets people to downtown stations where they will walk and ride transit instead of driving.

Bel himself left a comment pointing out that any transportation investment yields private benefits (which should probably be paid for by the user) and public benefits (which could be paid for by the government), and pointing us to an interesting study of the new Italian high-speed rail network (PDF). I think that's very important, but I would add that the public and private benefits are not a matter of universal agreement, and especially with the public benefits there will be people who disagree about the relative value of transit cross-subsidy or economic development or emissions reductions. The debate is not just a matter of how much a project affects these outcomes, but how much the outcomes matter.

With that in mind, let me try to clear up a few more things about return on investment. If our goals are to induce economic development then we'll be looking at measures like levels of employment and tax revenue generated by that development. If we don't care about any of that and we just want to make sure that this project doesn't bankrupt the state, we'll be focused on capital and operating outlays. Either way, density of development plays a role. Just as importantly, though, we need to look at the transportation system as a whole consisting of redundant bus, rail and private auto networks, and figure out the most cost-effective way to make use of it. It's idiotic to declaim the waste on high-speed rail while ignoring the ROI of the multitude of inefficient highway expansion and rehabilitation projects. As Chuck shows, development density improves the ROI of both road and transit infrastructure.

As you can see at the top of the page, my goals are to increase access and improve society while reducing pollution and carnage and avoiding resource depletion. Because of that I may look at individual measures like access to jobs and services, pollution, fatality and injury levels, and rate of depletion of the various natural resources used by transportation and development. Many of these metrics are sensitive to the density of residential, commercial and industrial development.

However, other than access, all those goals require getting people out of their cars. This means that I can look at VMT reduction as a long-term goal, and increasing the mode share of transit and walking in the short term. More importantly, there's a cycle of government and private investment in transit. The more transit ridership there is, the less subsidy will be required, and the more money that will be available for expanding the transit network. In addition, the more transit ridership there is, the more political support there will be for government investment in expanding the transit network. Conversely, the less driving there is, the less political support there will be for driving subsidies. Transit mode share is really key here, more important than any of the individual measures.

Transit mode share, in fact, is where density is least relevant. This may seem surprising, but only if you believe that density is the only way to control the relative value that people get from various modes. I'll talk more about that soon.

What does it mean to "support transit"?

Last week I singled out Richard Layman for repeating the chestnut "Spain doesn't have the population density to support economically many of the lines, based on ridership." Again, let me make clear that Richard is far from alone in assuming that density is required to support transit, and that his blog is informative, insightful and well worth reading for urban issues. He was also a good sport in leaving a comment on my post; unfortunately all the comments made it clear to me how deep the idea is ingrained in our understandings of transit.

A number of people have addressed this issue before. Richard mentions Steve Belmont and linked us to a scan from his book (see also David Alpert's take). Alon mentions Gary Barnes and his concept of "perceived density" (PDF); the Austin Contrarian has his own idea of perceived density.

I had a great idea for a phrase, "density is not destiny," but like most ideas it turns out that someone's thought of it before you; in this case it was Paul Mees, and Jarrett has an interesting discussion. But all these discussions are frustratingly myopic, assuming that the competing road network is a constant force of nature beyond political influence.

Instead of looking at the concept of "density," let's look at "support." What does it mean to support a transit line? Is it complete financial self-sufficiency, as Germà Bel demands for the Spanish high-speed network? If that's the case, then very few transportation projects anywhere would qualify. Is it the simple existence of the transit line? Then Newburgh's three-line transit system would qualify, since it exists, but that's not a very enlightening criterion. Is it a certain threshold of mode share, as the discussion at Greater Greater Washington would suggest? That's more promising, but it's not all.

Let's bring in some Strong Towns thinking. Chuck Marohn looks at any transportation project and asks, what is the return on investment? And it turns out the answer is connected to density. The ROI for a street, bus line, train line or ferry dock, it turns out, is dependent on the benefits derived from that investment. If it's a government investment, it has a "public ROI" indicating the benefits accrued to the public, whether in the form of tax revenue or any other goal.

ROI is the benefits divided by the costs. In transportation, sewers, utilities and other public projects, the costs are spread out geographically, so the ROI depends on the density of the benefits. That is where density comes in.

The population density to support my ass

I swear if I read one more time that such-and-such a place "doesn't have the population density to support" transit, or sidewalks, or high speed rail, or multifamily housing, or mixed-use development, or sushi restaurants, or anything other than Joel Kotkin's suburban American fantasy, I'm gonna spit. At this point all you urbanists, livable streets advocates and transit supporters really ought to know better. Yes, you, Richard Layman, but you're not alone so don't feel bad; you're just the most recent person to say it, who happened to set me off.

Layman is summarizing the myopic "lessons learned" in an article about Spain's high-speed rail system (don't miss the "next page" buttons!) by mainstream reporter Tim Sheehan of the Fresno Bee, based in part on an interview with political economist Germà Bel. Sheehan writes:

"There is no question whether (Spain's system) can cover its costs. It cannot," Bel said. "It actually has not recovered one single euro from the infrastructure investment. The government claims they are recovering the operating costs, but the numbers are not clear."

The busiest high-speed lines in the world are capable of making money, Bel said, including between Paris and Lyon, where about 25 million people ride the French TGV trains each year, and the Japanese Shinkansen trains between Tokyo and Osaka, which draw about 130 million riders a year.

"But this is not the case with any single line in Spain," Bel said. "The most crowded operation is Madrid-Barcelona, and it has not even had 6 million people in a year."

Robert Cruickshank took issue with Bel's argument and Sheehan's portrayal of it. He also faults Sheehan for holding highways to a double standard. What about Spain's highways? Are they half empty too? Do they pay for themselves, since many of them are tolled?

Note that Bel doesn't say anything about population density; I think that's something that Layman is reading into it. What he and the other analysts tell Sheehan is that the system doesn't have high enough ridership, which is not the same thing. In fact, Bel's own research fails to show that population density is a significant factor in urban transit ridership.

In 2010, Bel and his colleague Daniel Albalate did an amazing factor analysis (PDF of the 45 cities in the Mobility in Cities Database (yours for only $1,608 plus shipping!) and found that the factors that loaded most heavily on service demand were as follows:

Factor	Loading
GDP	0.797
PRIVATE_TIME (average time spent by private vehicle trip)	0.747
FLEET (fleet of vehicles available for public transport purposes)	0.553
MOTOR (number of private vehicles per capita)	-0.524
PRICE (average price charged to urban transport users)	-0.466
PARKING (number of parking spaces per thousand jobs in the CBD)	-0.221
DENS (urban population density)	-0.190
PUBSPEED (average speed of public transport vehicles in operation)	0.0722

Here's a quick note on how to read a factor analysis. A positive value means a positive correlation, so the higher the GDP, the higher the demand for transit. A negative value means a negative correlation, so the more private vehicles per thousand residents, the lower the demand for transit.

The key here is the absolute value of the loadings. The greater that value, the stronger the relationship between the factor and the dependent variable. In this case, the effect of GDP is more than ten times as much as the effect of transit speed. Note in particular that population density and transit vehicle speed have the loadings with the lowest absolute value.

Finally, remember that this shows correlation, not causation. It may well be that high transit demand causes large numbers of transit vehicles to be available (funny how that works!) and high population density, not the other way around.

Again, this article by Albalate and Bel refers to urban transit, not intercity rail, but the dynamics involved in intercity mode choice are similar to urban mode choice. The time difference (3.5 hours for AVE vs. 6 hours by private car), number of vehicles per capita, tolls and gas would all make a difference. Those are some lessons that California can learn from Spain, but as Cruickshank argues, Sheehan was predisposed to find problems with high-speed rail. Maybe Bel tried to tell him, but he wasn't listening for it?