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HSR and the Aerotropolis

Frankfurt Airport long-distance rail station - CC image from Heidas on Wiki

Alon Levy has a post up about the potential for high speed rail to fulfill the goals of ‘decongesting’ US airports. Alon looks at origin/destination pairs and compares the flight time to comparable HSR ranges where the technology has a chance to offer a superior travel time.

The takeaway is that the benefits for airport relief are likely bigger in California than they would be in the Northeast Corridor.  Assuming a fully built out rail system, this makes some intuitive sense: California’s big cities are arranged somewhat linearly along the coast/central valley, just as the NEC cities do along the fall line.  The big difference would appear to be the proximity of other cities – much of the California air traffic is intra-California travel:

Anonymouse in comments brings a good point about the distribution of short-haul travel within airport systems: there is often proportionately more of it at the secondary airports…

The five LA-area airports between them have 27.5% of their domestic traffic within 3-hour radius, but this splits as 21% at LAX, 35% at Long Beach, 37% at Santa Ana, 40% at Ontario, and 63% at Burbank. The three Bay Area airports between them have 19% of their domestic traffic going to LA and a total of 35% within 5-hour train radius, but this splits as 14% and 29% at SFO, 27% and 48% at San Jose, and 35% and 57% at Oakland.

In California, this isn’t a surprise, as SFO and LAX are the big international hubs.  In the Bay Area, SFO is next to the proposed line, but LAX is not.  Translating that to the NEC is different, however.  One element is adjacency – the NEC (or a short extension thereof) runs directly next to DCA, BWI, PHL, and EWR – of which only EWR is a major international hub.

This raises a few issues for HSR trips substituting for flights:  will HSR replace an entire trip, or just one leg of a trip?  If HSR is going to replace one leg of a trip, how easy does the HSR-Airport transfer have to be?  What kinds of trips would make sense for this kind of transfer, and are the best airports positioned along the line to handle them?

On the domestic/short haul flights, commenter Anonymouse writes:

In the Bay Area at least, there’s been a slow tendency for flights to get more concentrated at SFO, with OAK and SJC having mostly domestic flights, and most of those short hauls operated by Southwest. With an HSR line to LA, each of OAK and SJC can easily lose a quarter of its passengers overnight, and with good connections to San Diego, Las Vegas, and Reno, that could become half of all their traffic. SFO and LAX would lose some of their existing passengers, obviously, but not as many, thanks to the fact that they’re hubs. And that means that airlines are more likely to cut flights at the secondary airports, rather than SFO, thus filling the SFO capacity right back up with the passengers displaced from the secondary airports.

On the NEC, a similar retrenchment to the big airports would mean more traffic at IAD, EWR, and JFK.  These three are the busiest international airports along the NEC.  Dulles in particular is one of the few with room to grow, and grow substantially.  The one problem: Dulles (like JFK) isn’t adjacent to the NEC.

Maybe the more interesting case is DCA.  With no international facilities (save for border pre-clearance cities), DCA’s traffic is virtually all domestic.  DCA’s old noise-related perimeter rule also limits most of the destinations to a 1,250 mile radius.  The wiki summary of domestic destinations shows several ripe for rail substitutions (in bold):

Busiest Domestic Routes from DCA (May 2011 – April 2012)[26]
Rank Airport Passengers Carriers
1 Atlanta, Georgia 828,000 AirTran, Delta
2 Chicago (O’Hare), Illinois 697,000 American, United
3 Boston, Massachusetts 685,000 Delta, JetBlue, US Airways
4 Dallas/Fort Worth, Texas 489,000 American, US Airways
5 Miami, Florida 449,000 American
6 New York (LaGuardia), New York 362,000 Delta, US Airways
7 Orlando, Florida 350,000 AirTran, Delta, JetBlue, US Airways
8 Fort Lauderdale, Florida 315,000 JetBlue, Spirit, US Airways
9 Charlotte, North Carolina 294,000 US Airways
10 Houston, Texas 264,000 United

The same data for BWI:

Busiest domestic routes from BWI (May 2011 – April 2012)[33]
Rank City Passengers Airline(s)
1 Atlanta, Georgia 720,000 AirTran, Delta, Southwest
2 Boston, Massachusetts 549,000 AirTran, JetBlue, Southwest
3 Charlotte, North Carolina 483,000 AirTran, US Airways
4 Orlando, Florida 463,000 AirTran, Southwest
5 Detroit, Michigan 342,000 Delta, Southwest
6 Tampa, Florida 301,000 AirTran, Southwest
7 Denver, Colorado 294,000 Southwest, United
8 Providence, Rhode Island 293,000 Southwest
9 Fort Lauderdale, Florida 283,000 AirTran, Southwest
10 Manchester, NH 273,000 Southwest

These two airports would seem to be the candidates to see a lot of rail trip substitution, with Dulles remaining the region’s predominant international hub.

Again, the problem is that Dulles is not along the NEC, preventing the kind of air/rail connection you see in Frankfurt or in Paris.  Or, look at the top destination for both DCA and BWI – Atlanta.  Given Atlanta’s massive hub status, what kind of air-rail connection would be required to get passengers to use the train for the first leg of that journey? Making the connection to get an international flight at Frankfurt is one thing, but doing so in Atlanta is another – particularly if the rail and air terminals are not co-located.

Having a great HSR-Airport station at DCA or BWI is relatively easy (compared to, say, IAD).  Alon makes this observation about California:

Note, by the way, how California is planning the Oakland Airport Connector and considering an HSR station at Burbank Airport instead of downtown Burbank. Because if there’s one place Californians would really need to use HSR to get to, it’s an airport 63% of whose traffic competes with HSR.

Now, a DCA rail station has far more potential that just serving the airport (it would essentially replace the current Crystal City VRE station and could easily offer pedestrian connections to both Crystal City and to National Airport), and it would be far more than just the massive parking garage that is the BWI rail station.  Burbank (~2.5 million passengers a year) also isn’t anywhere near National Airport (~18 million passengers a year). So, what might the future look like for DCA and BWI in an age of ubiquitous HSR? Alon offers one possibility:

For New York, the best things that can be done then are to use larger planes on domestic flights, and find relief airports. In Japan, the domestic flights use widebodies, sometimes even 747s, and this has enabled Tokyo-Sapporo to grow to become the world’s highest-capacity air city pair. In the US there are more airlines and the city pairs are less thick, but there is still room for larger planes than 737s and 757s.

Changing DCA’s perimeter restriction could plausibly open the door to such a change, though security and airfield restrictions limit that to some degree. (Boeing did recently bring a 787 into DCA for display, and Delta did operate 767s into DCA to add passenger capacity prior to the Obama inauguration – would’ve been fun to be at Gravelly Point for that.) Larger planes, and potentially different destinations – if HSR changes the distribution of the airline hub model.

Commenter Jonathan English offers a competing hypothesis:

Unfortunately, major American airlines (compared with European and Asian airlines) are obsessed with frequency. They believe that they will only attract business travellers if they offer many flights per day, in many cases hourly or even more. This means that even if high-speed rail really eats into the number of people flying, airlines may just compensate by down-gauging from 737s and 320s to regional jets. They’ll still operate just as many flights and put the same pressure on runways.

Given the importance of frequency to transit, complaining about frequent air service might seem a bit ungrateful, but air travel isn’t really like transit.  Due to limited capacity and security, you must schedule in advance. Security, logistics, and airport location demands an early arrival.

Predicting what the air travel marketplace will look like in this hypothetical scenario is somewhat pointless – what if oil prices spike? What if there is political action on global warming resulting in a carbon tax or something like it? Air travel will most certainly still have a major (and a high value) role in linking these places, but exactly which places are linked could easily be disrupted.

Updating the reading list

CC image from sabeth718

It’s been a while since I’ve updated the reading list, so I’ve added several new (and several old) reads to the list. I also kept the link to my old (and no-longer supported) Google Reader shared items feed, while also adding the full del.ici.ous links feed.

I’ve got a few more books on my bookshelf that I’d like to add to the list.  Any suggestions for books/content to add?

Cities and the constructal law

CC image from Other Think

Several months ago, I picked up a copy of Design in Nature as an impulse buy at the bookstore. I was purchasing a gift and the cover caught my eye. A quick perusal of the jacket and a few pages of the introduction was enough for me to fork over the cash.  I didn’t get around to reading it until I had several airline flights this summer (with the accompanying missed connections) to dig into the book.

The basic premise of the book is that the similarities we see in nature (why trees and lightning bolts and river deltas share the same branch-like architecture) isn’t a coincidence, and it certainly isn’t the result of divine inspiration.  Rather, these similarities are explained via thermodynamics and the ‘constructal law‘ as coined by the author, Adrian Bejan.  The law states: “For a finite-size system to persist in time (to live), it must evolve in such a way that it provides easier access to the imposed currents that flow through it.”

In short, the flow systems and the laws of physics that govern them influence those similarities in design. From the wiki summary:

The constructal law represents three steps toward making “design in nature” a concept and law-based domain in science:

  1. Life is flow: all flow systems are live systems, the animate and the inanimate.
  2. Design generation and evolution is a phenomenon of physics.
  3. Designs have the universal tendency to evolve in a certain direction in time.[2]

The constructal law is a first principle of physics that accounts for all design and evolution in nature. It holds that shape and structure arises to facilitate flow. The designs that arise spontaneously in nature reflect this tendency: they allow entities to flow more easily – to measurably move more current farther and faster for less unit of useful energy consumed.[3] Rain drops, for example, coalesce and move together, generating rivulets, streams and the mighty river basins of the world because this design allows them to move more easily. The constructal law asks the question: Why does this design arise at all? Why can’t the water just seep through the ground? The constructal law provides this answer: Because the water flows better with design. The constructal law covers the tendency of nature to generate designs to facilitate flow.

Reading the book, I thought back to previous examples of similar observations of cities:

  • The similarities of subway networks across multiple cities (linked previously here)
  • The work of Geoffrey West on a universal theory of cities (also here), economies of scale and the benefits of agglomeration
  • Jarrett Walker’s analogies of transit systems as rivers (both here and here), particularly with the usefulness of drawing out key principles (e.g. ‘branching divides frequency’).
  • Any number of urban economic studies of agglomeration, innovation, and human capital – studying the flows of information in cities (examples here, here, and here, among many others)

Jarrett Walker’s recent Email of the Month post sparked me to write this.  Walker’s emailer, Kenny Easwaran, notes:

At the time, I was thinking of the various transportation systems we know of that aren’t designed by humans.  The main examples I could think of were things within the human body, and I noticed that things like the circulatory systems of animals and plants, and the digestive system of animals, seem to follow somewhat different trajectories from grids.  In particular, they either have a branching tree structure, or something more like an extended linear structure.

Having recently finished Adrian Bejan’s book on constructal theory, the analogy to tree-like systems immediately caught my eye. For me, Bejan’s description of all of these phenomena as flow systems ruled by common principles of physics helps shape my thinking, even if it is a bit vague.  Walker’s analogies of transit networks to rivers is a similar case.

 

Wayfinding challenges for WMATA’s Rush Plus

WMATA’s recent service change, branded as Rush Plus (probably over-promising things just a bit as “rush hour reinvented”), involved deviating from Metro’s fairly straightforward delineation of lines and services via color.  Metro’s increasingly complicated service pattern is getting to the point of requiring a similarly robust nomenclature for services.

When a rider speaks of the Red Line, they refer not just to a set of tracks but also the service that operates on them.  Even this wasn’t perfect, as many Red Line trains wouldn’t operate for the full line – they would short-turn at Grosvenor or Silver Spring.  GGW’s Metro Map contest identified each of the separate services Metro regularly runs, counting ten current services, plus the future Silver Line.  Ten services is obviously more than the five colors on Metro’s map.

More problematic is the fact that color and line terminus are no longer paired.  Yellow line trains can terminate at both Franconia-Springfield and Huntington; Orange line trains can terminate at both Largo and New Carrollton.

When devising a new map to show these service changes and to prepare for the introduction of the Silver Line, Metro opted to keep the map (and service nomenclature) that riders know well the same.  However, the increasingly complex service pattern demands nomenclature to match.

WMATA’s move towards using colored bullets to help identify train services helps:

However, those bullets still only identify the all-day services, not the ‘Rush Plus’ services.  WMATA’s in-station signage uses something else:

YL Rush Only service bullet, GR bullet. CC image from justgrimes.

The striping within the bullet matches the pattern for such services on Metro’s new map, but it just doesn’t read well on in-station signage:

Rush Plus signage at Gallery Place-Chinatown. Photo by author.

From afar (or in the above case, just standing at the platform), you can’t tell the difference between the rush-only YL bullet and the regular service YL bullet.  Which means that the bullet isn’t useful for wayfinding if the rider still needs to focus on their terminal destination.  A different rush-only YL bullet adds nothing.

One potential solution would be to take a lesson from a system that has lots of different services, operating on different lines (both are distinct concepts) – New York.  Differentiation among similarly routed services can be accomplished via graphical means.

    

For some rush-only, peak-direction-only services, New York’s diamond bullets might work as an example for Metro’s rush-only services. Regular Orange Line trains [identified as (OR) in shorthand] would go to New Carrollton, while rush-only trains [identified with a diamond <OR> bullet] would go to Largo.

This wouldn’t solve all of Metro’s service naming challenges – the fact that some rush-only services bring new service to places (like more trains to Largo) while other services do not (how most Yellow trains at the peak end at Mount Vernon Square, not the ‘regular’ listed terminus of Fort Totten) and that some service patterns are not rush-only (short-turning trains on the Red Line at Grosvenor and Silver Spring) makes a simple switch difficult. Still, there’s a need to change.

This isn’t the first time this issue has popped up, and so long as Metro’s services are getting more (and not less) complex, it won’t be going away anytime soon.

Streetcar lessons from France

Paris T3 - image from wikipedia - note the seven-segment vehicle, dedicated right of way, and grass tracks.

Last month, Yonah Freemark’s post on the rapid expansion of tramways in France caught my eye.  These systems offer several key lessons for the streetcar projects popping up across the US, as well as here in DC. The thinking is to make the tram different from just a streetcar – a transit option that isn’t much different from a bus in terms of geometry.

In many ways, this is about further blurring the already fuzzy distinction between light rail and a streetcar.

Some key takeways:

Give transit the edge:  For most cases, this would mean putting transit in a dedicated right of way.  Taking advantage of the urban design elements with grass tracks is nice, but the key element is the dedicated right of way to speed operations and increase capacity (call it mostly Jarrett Walker’s ‘Class B’ right of way).  Leaving an expensive investment to slog along in traffic like the bus would isn’t giving that investment the fullest chance to succeed.

One commenter notes the explicit trade-off:

US so-called light rail is more like a cheap suburban railway, with near absolute segregation, needing large compulsory purchases – again not endearing them to householders or shopkeepers. San Diego had one of the cheapest build costs, but even so had to pay $18 Million for the route – an old railway.

France seems to have decided, rather than buy up property, remove the cars which clutter up the street and replace by a tramway which more than doubles the street passenger throughput. A much better way of doing things.

Take advantage of capacity:  One of rail’s clear geometric advantages over bus is capacity.  The newer tramways in France take advantage of this with longer vehicles than the streetcars currently in service in the US. As an example, the T3 line in Paris makes use of 7-segment Alstom Citadis 402 trams, measuring in at approximately 140 feet long – more than doubling the per-vehicle capacity of the vehicles in use in Portland and Seattle.

Standardization saves money:  These new tramways are, for the most part, fairly standardized in both construction and in rolling stock, allowing for substantial cost savings.  Many of the vehicles feature modular construction, both adding flexibility while maintaining standardization and making procurement of replacement parts easier.  Standardization doesn’t mean a similar look, however – customize-able front ends allow each city to personalize the look and feel of their trams.

Go big or go home:  Well, sort of. Scale matters, both in producing a project large enough to be a successful link in the network and big enough to achieve some economies of scale.  The wiki graphic shows the scale of the tramway network in and around Paris alone:

Building at scale (and with a predictable pattern of expansion and reinvestment) helps control costs.

Moving US systems to this kind of standard could be seen in one of two ways: either in terms of removing a great deal of the over-engineering of US light rail systems, or in terms of increasing the standards of US Streetcar systems.  Given the length of some of DC’s proposed streetcar lines, offering this kind of advantage to transit would be a sure-fire way to give these investments every chance to succeed not just as economic development projects, but as transportation projects as well.

Urban skiing above the Arctic Circle

[iframe_loader src=”http://player.vimeo.com/video/44652785″ width=”600″ height=”338″]

Not unlike the video of tiny Jackson Hole, I love a good ski movie. Combining it with post-industrial soviet urban landscapes from the Murmansk Oblast – even better.

Hat tip to the folks at Atlantic Cities for finding it. It took me a while to figure out how to fix the WordPress iframe loader, but I can now embed Vimeo stuff again.

More from these Finns here – in old Scandinavian mining towns:

[iframe_loader src=”http://player.vimeo.com/video/22300621″ width=”600″ height=”338″]

…and in Sarajevo, including some transit-oriented skiing:

[iframe_loader src=”http://player.vimeo.com/video/39202260″ width=”600″ height=”338″]

Video credits:

1. Nipwitz – Russia from Flatlight Films on Vimeo.

2. Nipwitz Two from Flatlight Films on Vimeo.

3. Nipwitz – Sarajevo from Flatlight Films on Vimeo.

Density links – process and constraints

Zoning notice from Burlington, VT - CC image from Don Shall

The ‘right’ density: In the process of putting this post together, I missed Ryan Avent’s piece in The Economist, mentioning some of the broader consequences of land use regulation constraints.  It’s a great summary of some of the key issues regarding density, constraints to growth, levels of governance, and our regulatory processes.    The genesis for the discussion is Facebook’s ability to spark a boom in Silicon Valley following their IPO.  Avent documents the constraints to this (and any other development) and the macroeconomic implications.

Avent leaves a footnote about what the ‘right’ level of density is, offering another criticism of Richard Florida’s recent piece on the subject. Avent writes:

Some urbanists claim that it’s important to cultivate the “right” density to boost innovative activity, and that tall buildings aren’t compatible with this. See this recent Richard Florida piece as an example. This strikes me as mistaken on multiple levels. I have very little confidence in the ability of planners to understand what a particular density is accomplishing and whether the “interactions facilitated” by shorter buildings either exist or are large enough to offset the higher real-estate and labour costs to which they contribute. It does not appear that technology companies have had trouble colonising central San Francisco or New York, despite the significantly greater verticality of those places relative to, say, Mountain View. And space is mostly fungible. Even if we assume that tech companies prefer short buildings while professional firms and households are happy in tall ones, the failure to provide ample supply for the latter uses will crowd out some of the former. That is, maybe the construction of lots of new residential and office highrises in San Francisco doesn’t attract a single tech firm to the new towers. The new construction will nonetheless place substantial downward pressure on rents, attracting lots of new people to the region and making it easier to start a business.

The focus on the ‘right’ density for innovation seems quite far-fetched and unsupported by evidence.  Some planners will indeed offer all sorts of reasons to limit heights of buildings, but facilitating greater innovation is not usually the stated reason.

Michael Lewyn offers a line-by-line takedown of a similar line of thinking from Ed McMahon (linked previously here). Well worth a read, despite the use of all caps.

Planning and process:  There are two competing issues that Avent touches on, however.  One is the content of the land use regulations, their substance and their scope.  That is, the kind of stuff they allow and disallow.   The other is the process of making these land use decisions.

Over the weekend, the New York Times featured a profile of New York’s planning chief, Amanda Burden.  A few things jump out: under Burden’s leadership, the planning department has substantially upzoned many areas of the city:

Since 2002, when she was appointed to head City Planning, she has overseen the wholesale rezoning of the city, with 115 rezoning plans covering more than 10,300 blocks; by the end of her administration, the department is expected to have rezoned about 40 percent of New York, an unprecedented number.

However, while the content of the regulations has increased, the process has not gotten simpler:

But that attention to detail has also received criticism. Ms. Burden’s belief in contextual zoning, for example, under which new developments in a neighborhood are required to be in the height and style of surrounding structures, leads to “profoundly conservative building,” said Julia Vitullo-Martin, a senior fellow at the Regional Plan Associationand director of its Center for Urban Innovation. “New York’s greatness as the dominant skyscraper city of the 20th century was the result of bold building, but the local zeitgeist has switched from big and bold to keeping everything small, nondescript and similar to everything else in the neighborhood.”

It has also become common under Ms. Burden’s leadership for developers and their architects to have to negotiate their designs with City Planning. “Development has become a game of second-guessing,” Ms. Vitullo-Martin said. “What will Amanda think of my project? What will I need to compromise on?

“There really doesn’t seem to be any true as-of-right development anymore,” she added, referring to the ability to build without obtaining permits or other approvals.

This strikes me as one of the fundamental tensions of urban development.  Much of it will follow the path of least resistance, building what is allowed by right due to the easier process. Chris Leinberger always made a point to emphasize how reform must make doing the right thing also the easy thing.  This is more about making the bad approach just as hard as the right approach.

In an ideal world, it would be best to make doing the right thing the easy thing; the by-right thing for developers.  You could reduce the constraint of the code’s substance while also reducing the procedural barriers to building – the timeline for approval in New York is significant:

FOR developers, the clock is ticking. Though the Bloomberg administration won’t leave office for 19 months, most projects that require rezoning or other Planning Department approval can take at least 18 months to get through the process. And the administration’s overall friendliness to development means that most builders with projects on the drawing board are scurrying to get them passed before the term’s end, rather than face the uncertainty of the next administration.

However, I’m curious if there is an absolute tradeoff between content and process.  Richard Layman advocates for precisely that – the reduction of by-right allowances with the goal of improving development outcomes.  I’m not sold that the tradeoff is absolute, however – that the only way to improve outcomes is to increase the control of the process over development.  Instead, the bar for by-right development should be higher, but without extra procedural hurdles.

Nonetheless, I am interested in seeing where exactly the borders between those tradeoffs are.  There’s also the question of personality and uncertainty – what does the rush to get approvals before Burden leaves office say about the longevity and sustainability of that regulatory mechanism? Does it become completely reliant on the people in a given office?

Open questions, all – I’m uncertain about the nature of those tradeoffs.

The wrong relationships: Echoing Richard Florida’s points about density and skyscrapers being nothing but ‘vertical cul-de-sacs’, the blog Walkable DFW unloads a lot of reasons to hate skyscrapers, none of which stand up to a closer reading.

An example.  Increased density has diminishing returns for efficient transportation:  this is true for transit ridership, but that’s because once you get to high levels of density, you don’t need transit at all – you just walk. Accessibility wins over mobility.

There are lots of other problematic statements, including some cherrypicked density datapoints from Barcelona and New York, but one in particular caught my eye: “stretching buildings upwards has the same effect as stretching them outwards.” That is, he claims building up is just as inefficient as sprawl:

I often lament living on the 19th floor.  I often walk to work.  But I still experience rush hour:  waiting for the elevators before and after typical work hours (often as much as 10 minutes if a few of the elevators are down, which invariably some always are).

I only bring this up for a chance to link to this excellent 2008 New Yorker piece on the secret lives of elevators. It would seem that this blogger’s building is under-elevated – though I would posit that’s not a particularly good reason to throw the baby out with the bathwater.

 

What do we mean by ‘density’?

Greenwich Village - CC image from lumierefl

A few more thoughts on recent discussions of density.  Better Cities and Towns offers a summary of Richard Florida’s recent speech (video is corrupted, unfortunately – it gets very choppy 1/3 the way through) at CNU. The twitter summary: quality of place trumps density.

Like previous discussions on the topic, I can’t help but argue semantics. Quality of place is no doubt extremely important – but I would argue it doesn’t trump density at all.  Rather, density is a somewhat independent variable. Density is an abstraction, it is merely the concept of how much stuff is in a given space.  For many discussions, whether on innovation or affordability or vitality, I would present density as the necessary-but-not-sufficient condition that makes it all work.  With that in mind, framing some other factor as one that ‘trumps’ (which I read as if I were playing cards: outranks, surpasses) density seems wrong.

Don’t conflate density and design: From the Better Cities and Towns summary:

One of the false statements is that density and skyscrapers are the key ingredients to urban vitality and innovation. “This rush to density, this idea that density creates economic growth,” is wrong, he said. “It’s the creation of real, walkable urban environments that stir the human spirit. Skyscraper communities are vertical suburbs, where it is lonely at the top. The kind of density we want is a ‘Jane Jacobs density.’”

What is the ‘Jane Jacobs density’?  Is it that of her home in Death and Life, the West Village?  If so, it’s worth remembering that the West Village is very dense.  The 2010 Census (easily accessed with the New York Times’ handy mapping tool) shows the West Village census tracts with population densities in the range of 80,000-100,000 people per sq. mile.

My good friend Mike Lydon linked to a review of sorts of Miami’s Brickell neighborhood, noting many of the urban design deficiencies of the place. Craig Chester writes:

Now, I enjoy Brickell primarily because I can walk for nearly all of my basic human needs – groceries, a barber, a slice of pizza etc. It’s also well-served by MetroRail and Metro Mover, both accessible from my doorstep. It’s a rare Miami neighborhood in that regard. But increasingly, I find myself questioning if Brickell is a “walkable environment that stirs the human spirit” or merely just a semi-walkable streetscape in the shadows of impersonal towers functioning as suburbs in the sky.

First, some context.  Brickell’s density from the 2010 Census tops out at 77,000 people per sq. mile in one census tract – surrounded by tracts with much lower population densities.  The max there, in other words, is lower than that of the West Village – and the West Village is bordered by residential areas with even greater population densities.

Chester continues with a number of critiques on the urban design of the area – how the buildings interact with the streets, how the retail spaces are arranged, how the neighborhood makes use of the transportation systems, and so on.  The descriptions are all fascinating, but I don’t see density as the primary (or even secondary) culprit in any of Chester’s critiques.

I increasingly find myself leaving Brickell on my bicycle in search of more authentic urban experiences found elsewhere in the city. Actually, I need to leave Brickell just to go to a bookstore or bicycle shop….

….usually found in “Jane Jacobs” density.

I’ve not visited the area so I can’t speak to the accuracy of Chester’s critique in person, but I have no reason to doubt the descriptions of the place.  However, I think the conclusion is all wrong (echoed by the language Florida uses), and sets up a false dichotomy (and therefore a false tradeoff) between density and place.  Searching for a place with ‘Jane Jacobs’ qualities is one thing, but extrapolating that to some magic ‘Jane Jacobs density’ isn’t well supported.

Don’t conflate density and the ‘human scale.’  Another tidbit from the Better Cities and Towns summary of Florida’s speech:

The urban/suburban debate is likewise false, he said. “Great communities and great neighborhoods pretty much look the same,” he said. They are human-scale, include a mix of uses, and are close to transit. “These are the kind of things that people desire, and it is not just in the urban core that you find them,” he said.

I fully agree that the urban/suburban distinction is mostly useless, but the relentless focus on the human scale is another one of those turns of phrase that can be easily misconstrued.  While there’s some relation to the absolute scale (building heights, etc), the tradeoffs between human scaled look and feel of a place (e.g. design) and the absolute mass of stuff (e.g. density) are not absolute – as sometimes implied. There’s plenty of room to go up, to be more dense, without sacrificing the human scale – the key is in how you do it.

Density (eventually) requires height, but height does not prevent place.  Alon Levy has made the point about the need for height to achieve density at some point. While there’s a tremendous opportunity for the ‘missing middle‘ in most places, many others have market conditions that already demand more space.  It’s also useful to remember that density is just an abstraction of stuff/area – the kinds of stuff you’re measuring can vary.  Tall Manhattan and short Paris are both very dense, but that’s because the tall stuff isn’t captured in the metric of population density:

Unfortunately, this point is easy to miss, since the headline figure of density is residents per unit of area, and residential skyscrapers are rare. Skyscraper-ridden Manhattan and height-limited Paris have about the same residential density, but Manhattan’s skyscrapers are predominantly commercial. Aside from project towers, Manhattan’s residential urban form is mid-rise, with most buildings not exceeding 6-12 floors; this is similar to Paris.

So, yes, we must build up at some point:

To get higher density, one must build higher. Some parts of Manhattan do: the Upper East Side and Upper West Side have a fair number of buildings in the 20-30 story range, and although as Charlie computes only 1% of New York City’s residents live above the 19th floor, the proportion is much higher on the Upper East Side and Upper West Side, and becomes even higher if one relaxes the limit from 20 floors to 12, already well beyond the limit traditional urbanists and high-rise opponents accept (Christopher Alexander proposes 5 as the limit).

Height does not prevent place – human scaled urban design can work in incredibly dense places with tall buildings, because the key elements to the human experience is what goes on at street level.  New Yorkers don’t look up at their skyscrapers because it’s not a natural position for a human.  Our HDTV screens mimic our own physiology – wide, peripheral vision with limited vertical views.  Develop the first 5 or so stories well, provide some setbacks for the taller portions above that, and you’ll do just fine for creating a sense of place at a human scale.  Adherence to this scale need not be absolute.

Beware statements of universality. It’s interesting to see one kind of density (even if people are really arguing for place, not density) pushed out as the ‘right’ level of density.  There’s a big difference between observing various geometric rules of an environment and pushing one’s taste, via observation, as if it were the rule.

The argument about the “Jane Jacobs density” is a great example.  West Village densities would represent a tremendous increase in most places around the US – just not in New York.  New York is the exceptional case.  Achieving Greenwich Village densities in other cities might be a tremendous increase – likewise, maintaining Greenwich Village densities in New York’s context (given the market conditions, etc) is likely a severe constraint on supply (see Ed Glaeser).

So, what makes the ‘Jane Jacobs density’ the right density?  How can anyone even pretend to know what that would be, without considering the context, the market conditions, the baseline of development, etc?  One element of Ryan Avent’s The Gated City that I admire was his steadfast refusal to state which level of density is ‘correct’ or ‘right’ or ‘good,’ but rather to focus on the process that cities go about changing their densities (and how that process is currently constrained by things like zoning codes).

Likewise, Ed Glaeser’s Triumph of the City focused on the market aspects of density, as far as density and overall supply are related.  So long as the cost of new stuff (housing, offices, etc) is fairly even with the cost of construction, then you’ve got a fairly efficient market.  This could be a step towards defining what the ‘right’ density is, but of course that answer is going to provide a different number in every situation.

What would change with driverless cars?

Robocar electronics - CC image from Steve Jurvetson

If we can agree that technology doesn’t change geometry, and therefore driverless cars won’t substantially change the fundamental capacity and spatial requirements of our current auto-based transportation systems, then what would they change?

Chris Bradford takes a stab at this question, taking note of Matt Ygleisas’s prediction of reduced demand for parking. Matt cites the idea of having a driverless car drop you off at a commuter rail station in the morning in order to make use of the higher capacity rail system to enter the city (thanks to the relevant geometries of rapid transit), while the car would then return to your house – eliminating the need for more car storage at the rail station. Chris takes that one step further, noting that with a tireless ‘driver,’ the needs for vehicle storage wouldn’t need to use a set space at all, but could be accomplished through cruising.

While both ideas would reduce the need for parking spaces, they would also increase the VMT for any given trip – either through cruising for parking or for increased deadhead trips, further clogging the streets. This might not be a problem in certain cases where congestion isn’t currently an issue, but it sure wouldn’t help in places where congestion is already a problem.  Bradford notes this:

In fact, this perfectly rational practice will probably be so harmful, so patently selfish, so despised that it will be necessary to outlaw it. Which means everyone will still have to find a spot for his car, driverless or not. Which means that, despite the title of this post, we might not see a robocar apocalypse after all, or a parking bubble, either (other than the existing bubble that local governments have created with underpriced street parking and mandatory parking minimums.)

Perhaps the most interesting application, then, isn’t the need to store a car for personal use (given the issues of storage raised above), but to allow that car to be used productively by someone else.  A driverless taxi, otherwise (hence my choice for my previous post’s image of Total Recall’s Johnny Cab – I don’t know if the new version of the film this summer will depict the Johnny Cab, if it does so at all).

You can already see the convergence of different car ownership models.  A taxi is owned by an operator, they provides rides for hire, charging you for the convenience of the trip in their car and for not having to drive yourself. Compare that to the current point-to-point carsharing model like Car2Go, and the only real difference is the driver.  Both charge based on time and/or distance traveled, both offer point to point trips in a vehicle you don’t own.

While the cost of these robocars would likely come down over time, they’d still be more expensive than regular ol’ human-driven cars, meaning that the trends towards collaborative consumption would continue, and the robocars would serve their best use as taxis.  The value of owning one yourself would be limited, unless you had a ton of disposable income.

As Matt Yglesias put it, “imagine a world of cheap, ubiquitous taxis.”  The net impact would be favorable to cities and those who live in them.  The limits of the automotive geometry and capacity wouldn’t fundamentally change, so this would still be a premium service over much higher capacity mass rapid transportation.  The benefits of owning a car would continue to decline in urban areas, as would the cost of the auto-based alternatives (like taxis).

Urban density and innovation

CC image from Seth Waite

One more round on density – this time focusing on affordability via the tangentially related prospect of innovative and creative economies.

Richard Florida chimed in at The Atlantic Cities, asking this:

Stop and think for a moment: What kind of environments spur new innovation, start-ups and high-tech industries? Can you name one instance, one, of this sort of creative destruction occurring in high-rise office or residential towers, in skyscraper districts? The answer is no. High-rise districts typically house either corporate office functions or residences. During the post-war era, while they were building these towers for their corporate functions, large U.S. companies housed their research scientists in green, low-rise R&D campuses, where the scientists could interact more freely.

The backlash on Twitter was swift and merciless – with plenty of anecdotes of innovative, creative destruction going on in high rise office towers.  Timothy Lee at Forbes noted that Florida is probably a bit sloppy with his terminology here, equating a high rise with an expensive building.  Citing Jane Jacobs, he writes:

While Jacobs framed this principle as being about old buildings, it was really about cheap buildings. Young innovators need to keep their expenses down to maximize the time they can spend on their project and minimize time spent waiting tables. And when they start companies, they need to minimize their rent to maximize their chances of reaching profitability before they run out of money.

So Florida is right that innovators almost never start their careers in gleaming office towers. But it’s a mistake to conclude from that that an excess of skyscrapers makes a city bad for innovation. The innovators themselves won’t move into the skyscrapers, but the construction of more housing units places general downward pressure on rents. That allows innovators to move into the less swanky, more affordable, homes and offices that were abandoned by the people who do move into the skyscrapers.

That is, those older high rises will filter down to lower rents and therefore be attractive to startups and other innovative uses (see the case of Silicon Alley in New York – Florida mentions it as a ‘low rise’ example, but equating that to a Sunnyvale office park is quite a leap).  The actual form of the building doesn’t play nearly as much of a role as Florida would imply.  The jury is out on the role of the city form and urban design (though I have my guesses).

As mentioned above, Florida was a bit sloppy in what he considered a high rise, later commenting that 14-20 stories is fine, but taller heights might not work. Perhaps it’s my time in DC that’s shifted my perspective on tall buildings, but I would argue that 14-20 stories is plenty tall enough to be considered a high rise.  Regardless of my definition of a high rise, the question is then – what is tall enough, dense enough?  David Schleicher and Ryan Avent make the case that you can’t know that in advance.

Some more back and forth shifted the discussion to the tradeoffs inherent to density, but in DC that discussion of density can’t be considered in isolation of other constraints on development – the kind that see low rent buildings redeveloped rather than letting them filter down where innovation might take hold (given several other key ingredients).  The gleaming new corporate office tower reduce rent pressure on the older high rise office buildings, as well as smaller and shorter legacy structures.

It’s somewhat curious to see a discussion about the power of markets to foster innovation when talking about the massive constraints on real estate. The creative destruction of capitalism at its best in the idealized start-up office park Florida described, yet that physical outcome is anything but a free market outcome.  Timothy Lee makes the case that if the real estate markets were more free to operate, the Bay Area would have 4 million more people living there today. The Bay Area’s natural geography limits sprawl and favors density, as well – if given the chance to grow.

That, of course, is a big if. Matt Yglesias takes note of some dense residential construction proposed for Downtown San Jose – precisely the kind of place that you would expect to grow more densely if allowed:

The San Jose and San Francisco metropolitan areas are ground zero for the phenomenon of regulations that provide for an insufficient quantity of construction in America’s high-value areas, so I was somewhat surprised to read an article about the municipality of San Jose implementing an incentive program to encourage more residential investment in the city. Why are incentives needed? The incentives, however, all turn out to be nothing more than temporary relaxation of anti-development rules:

The incentive package includes a 50 percent break in construction taxes; a 50 percent reduction in fees that downtown residential developers must set aside for a park as a portion of their project costs; expedited reviews by the planning department staff and eliminating a city requirement for an expensive air container system for firefighters in high-rise buildings.

What you have here are an explicit tax on construction, a de facto tax on construction, a regulatory barrier to construction, and a second regulatory barrier to construction. The “incentives” are relief from those barriers if your projects breaks ground by 2013.

From Wired (cited in Timothy Lee’s piece above):

As an investor Hartz points to the usual signs of too much money-chasing deals. The billboards on highway 101 between San Francisco and Silicon Valley touting startups no one has heard of. The bus stop signs in tech-heavy locales like Mountain View and Palo Alto advertising scads of engineering jobs.

“Everyone is competing for the same people, going after the same real estate, the same support services,” Hartz says. “The natural resources of the startup world are getting scarcer and scarcer, and the cost is getting higher and higher. It’s all an outgrowth of an abundance of capital.”

Lee’s point (same as Yglesias’s) is that the constraints on some of those resources aren’t as natural as you might think.