Tag Archives: grids

Disasters: the more things change, the more they stay the same

CC image from davecito

Two pieces on the challenges in re-building following a disaster. The first, from Lydia DePillis at the New Republic, on the challenges Brad Pitt has encountered in his rebuilding efforts in post-Katrina New Orleans:

But for a while now, Make It Right [ed- Brad Pitt’s charity foundation] has been having trouble enticing people to buy their made-to-order homes. The neighborhood has turned into a retirement-community version of its former self; the ward’s other former residents are dead or settled elsewhere. Construction on the cutting-edge designs has run into more than its share of complications, like mold plaguing walls built with untested material, and averaged upwards of $400,000 per house. Although costs have come down to around half that number, Make It Right is struggling to finance the rest of the 150 homes it promised, using revenue from other projects in Newark and Kansas City to supplement its dwindling pot of Hollywood cash. Now, in a wrenching deviation from its original mission, the non-profit has decided to open up to buyers who didn’t live in the neighborhood before Katrina.

But there’s a Catch-22: The neighborhood doesn’t have enough residents to attract many stores and services, and prospective buyers end up elsewhere because the neighborhood doesn’t have enough stores and services. So about 90 households, primarily elderly people like Guy, are living in futuristic homes that most Americans would covet, and yet there’s not a supermarket—or even a fast food restaurant—for miles.

The core challenge is meshing the reality of what conditions are required to successfully re-build a neighborhood following a disaster with the desires of the community, who (understandably) would like things to be simply a better version of what was there before:

If the Lower Ninth has any chance at becoming a livable community, new people are going to have to move in. But the young people who flooded the city after the waters receded are still finding plenty of room in the hipper neighborhoods, like the Marigny and the Bywater, that retained more of their historic housing stock. And the city seems determined to maintain the Lower Ninth’s structural disadvantage in this regard: Although a 2009 analysis of residential market potential showed that only about 20 percent of the existing demand was for single-family detached homes, that’s how the neighborhood has seen itself, and how it wants to remain. Even when a developer proposed the kind of dense, multifamily project that would attract the kind of amenities everybody says they want, residents howled in protest.1

“It’s always been a single-family neighborhood, and that was the community’s desires were after Katrina, and I think it will go back as a single-family neighborhood,” says Jeff Hebert, director of the New Orleans Redevelopment Authority.

The second piece is from Bob Ellickson on street grids (hat tip to David Schleicher), including a substantial discussion of the permanence they have over time – particularly noting how street grids rarely change much following substantial disasters (examples include post-war Hiroshima; post-fire Chicago; and post-Katrina New Orleans) that open the door for re-imagining and re-building the city.

The abstract:

People congregate in cities to improve their prospects for social and economic interactions. As Jane Jacobs recognized, the layout of streets in a city’s central business district can significantly affect individuals’ ability to obtain the agglomeration benefits that they seek. The costs and benefits of alternative street designs are capitalized into the value of abutting lots. A planner of a street layout, as a rule of thumb, should seek to maximize the market value of the private lots within the layout. By this criterion, the street grid characteristic of the downtowns of most U.S. cities is largely successful. Although a grid layout has aesthetic shortcomings, it helps those who frequent a downtown to orient themselves and move about. A grid also is conducive to the creation of rectangular lots, which are ideal for siting structures and minimizing disputes between abutting landowners. Major changes in street layouts, such as those accomplished by Baron Haussmann in Paris and Robert Moses in New York City, are unusual and typically occur in bursts. Surprisingly, the aftermath of a disaster that has destroyed much of a city is not a propitious occasion for the revamping of street locations.

In the second half of the paper, Ellickson discusses the path dependence of a street layout once it is established, finding that 88% of street centerlines from the 19th century in select cities remain the same today. Even in places like Chicago that saw near complete destruction of the city retained 99% of street centerlines from the 1850s. Ellickson suggests that legal reasons and property rights contribute to this path dependence, but the political costs of change and the sense of place from residents are also important considerations.

The link between Ellickson and DePillis emerges in Ellickson’s discussion of these reasons for the path dependence of street grids, stemming from a desire to maintain the status quo:

A second downbeat theory would attribute some of the stickiness of street locations to psychological dispositions that may be ephemeral. Most city residents, for example, have a “sense of place.” Most of them also have a bias that favors maintenance of the status quo. They appraise the prospect of a loss from a given reference point to be more momentous than the prospect of an equivalent gain. When contemplating a proposed rejiggering of local streets, city officials, landowners and residents thus are all likely to exaggerate the costs of losing a street right-of-way, and to undervalue the benefits of gaining a new one.

Another urbanist reason for everyone to read Thinking Fast and Slow!

Ellickson’s other discussion of street grids is well worth reading, but the implications of the path dependence of street grids (and the difficulty of changing the intensity of land uses) raise some interesting issues for places like Tysons Corner and the proposed street grid.  Adding more streets to a superblock layout is certainly a different challenge than removing/re-aligning streets in an existing network, but the central point about the path dependence of streets raises serious issues for the promise of retrofitting suburbia.

Observations from San Francisco

As a nice respite to DC’s heat, I was able to spend the last week in California – including several days in San Francisco.  Some thoughts and observations from the trip:

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Hills and Grids: Gridded streets have plenty of benefits, to be sure – but the downside is that they do not react to topography.  San Francisco provides the extreme example.  The city has even preserved the right of way where topography makes streets impossible.  My own adventure to the top of Telegraph Hill included ascending the Greenwich Street stairs.

Surely, relaxing the grid would offer opportunities for a more understanding development pattern.  Nevertheless, the spaces along the staircases are certainly interesting, as are some of the extremely steep streets.  Such a pattern would not work in a colder climate that has to deal with ice and snow on a regular basis, however – lest you end up like these poor folks in Portland.

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Trucks and Buses not advised.  Um, yeah.

Trolleybuses: As a direct response to the city’s grade issues, the electric-powered trolley buses are a great solution.  The overhead wires for the buses can be a little obtrusive – but they are not nearly as much of a visual blight as the broader patchwork of utility wires strung from house to house and pole to pole.

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Zero emissions, but the wires (like rails) do act as a visual cue for a newcomer to the city (like myself) to find a bus line when I need one.  That’s a plus.

Signage: Actual signs telling you where you are or what transit line to take, however, are sorely lacking – particularly for Muni and BART.

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We can do better than this – the BART platform at Montgomery station.  The boarding signs for various train lengths is nice, but not all that intuitive – but actually determining which station you’re at when the train arrives is another challenge entirely.  Similarly, on the Muni lines that turn into streetcar routes in the outer neighborhoods, signage at the larger stations is almost non-existent – certainly not useful for a first time rider.

That said – Muni’s route symbology is incredibly easy to understand.  Each line is assigned a name (corresponding to the main street it travels on), a letter (as a single symbol) and a color.  It’s something I think Metro could learn from as its route structure becomes more and more complex.

Wayfinding signage around town, however, was much better.  Kiosks offered maps, highlighted transit routes, and in general provided very useful information – even potential ferry routes, for example:

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My favorite ‘signs’, however, where the ones doing double duty – the public toilets:

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Granted, the actual map here is faded and hard to read, but the presence of a self-cleaning public toilet in a popular tourist area like this is priceless.  Thanks to nature’s urges, I never had a chance to actually use one – but the process seems quite self-explanatory.  If not, there are simple instructions:

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This particular toilet is from JCDecaux, the same outdoor advertising firm that operates Paris’ Velib bikesharing system.

Streetcars: The F Market line’s heritage streetcars are both interesting to see on the street and also an effective part of the transit network.  They’re also quite popular:

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One note about these old PCC cars – when you’re standing (as I was while taking this picture), it’s extremely difficult to see out the small windows of these old rail cars to determine where you are – especially with Muni’s aforementioned lack of quickly visible signage.  The PCC car wiki page talks about “standee windows,” but these weren’t of much help to me.

From the outside, the diverse colors of the various liveries from around the world Muni opts to use are fantastic.

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The liveries include this lovely pastel DC Transit paint job.

More (perhaps) to come later.

Weekend reading

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Excuse my timing on this, as this doesn’t leave much weekend to play with – but here are some items worth noting from the previous week or so:

Streetcars bridge the gaps: Yonah Freemark has an excellent post on DC’s evolving streetcar network and its ability to fill the gaps in Metro’s network.  Yonah’s excellent visuals (as usual) help frame the discussion.

New maps: New York gets a new map – Second Ave Sagas has the breakdown.  The map decreases clutter, though nothing compared to the more schematic designs for other systems.

Metro too cluttered: Speaking of clutter, Massimo Vignelli thinks Metro’s gotten too cluttered since he and Harry Weese came up with the signage scheme for the system decades ago.

Congestion pricing:

Grid vs. Sac: David Alpert notes a (perhaps the only) redeeming quality of the cul de sac; Jarret Walker notes the many advantages of gridded street networks.