Saturday, May 28, 2011

Cars, Pedestrians and Safe Streets

Is New York really the 13th most dangerous large city in the country for pedestrians?   A study reported on earlier this week at Streetsblog shows New York, somewhat surprisingly, to have a pedestrian fatality rate comparable to such car-friendly cities as Atlanta, Houston and Los Angeles. 

Regardless of the reason for these findings, the study I think does show one thing clearly: to reduce pedestrian fatalities to near zero, a city has around two options:
The Modernist solution: total pedestrian segregation.
  • Remove pedestrians from the city to the extent possible, or segregate them.
  • Remove cars from the city, or greatly constrain them.
Reflecting the first option is the idealized auto-dependent city of the early Modernist period, at right: a mocked-up American version of the Corbusian Ville Contemporaine filmed for the 1939 World's Fair, where all pedestrians are strictly segregated in recognition of the incompatibility of high-speed traffic arterials and human beings on foot (a more  localized example is the enclosed mall).  On the other hand, a car-free city such as Venice also has, unsurprisingly, a very low pedestrian fatality rate.

By contrast, in dense urban areas where large numbers of pedestrians and high-speed traffic share the streets, it appears a certain rate of pedestrian deaths is inevitable regardless of the measures which are taken to redesign street layouts.  Presumably this is due to induced pedestrian traffic: as an urban environment becomes more pleasant for pedestrians, pedestrian activity will rise in response, resulting in a numerical increase in fatalities even as the per capita fatality rate falls.  If the new pedestrian volume does not come at the expense of more dangerous automobile use (e.g. if people drive to the pedestrian-friendly area), the number of total transit-related fatalities may remain essentially the same.  Possibly this explains why cities of such varying pedestrian friendliness have roughly similar fatality rates: New York (1.9/100,000); Houston (2.0); Los Angeles (2.0); San Francisco (1.6); Atlanta (1.6); Philadelphia (1.7); Denver (1.7).  

Running the gauntlet, 3rd Avenue, NYC.
This is why I think Jane Jacobs was on point in when, in terms of improving the city's streets and other public spaces, she referred to "an attrition of automobiles by cities" (Death and Life, p. 474) rather than today's "efforts to improve pedestrian safety."  The difference may seem minor, but Jacobs' statement identifies the culprit not as insufficient accommodation for people on foot — which implicitly acknowledges the primacy, or at least inevitability, of the automobile — but the automobile itself, the culprit behind pedestrian deaths along suburban arterials and urban streets alike.

Jacobs envisioned a long-term strategy in which pedestrians would, bit by bit, encroach upon and reclaim the public realm from the car.  This is quite different from a modern Complete Streets approach, which at best seeks equality for pedestrians, rather than privilege, and which at worst, as Strong Towns Blog has shown, results in over-engineered, car-friendly thoroughfares where sidewalks and bike lanes are little more than an expensive afterthought.  To fully address street safety, the conception of the role of the car in urban settings could stand to take a bit more inspiration from Jacobs' point of view.

See also:  Are Narrow Streets A Realistic Objective?

(h/t Pedestrian Observations).

Tuesday, May 24, 2011

Streetcar Visions: Transportation in Bob Dylan's Music

Greenwich Village, but not a true narrow street.
Over at The Infrastructurist, Eric Jaffe has a great post up in recognition of Bob Dylan's 70th birthday that anyone with even a passing interest in Bob really ought to check out.  Combining infrastructure and Bob Dylan?  Yes, it can be done, and with fascinating commentary on each of the chosen songs.  At the cost of giving away my own longtime interest in Dylan's music, and for the sake of doing a purely fun post, I thought I'd add a list of my own on transportation in Dylan's songwriting (the former a subject I don't write about much, since it's done so well elsewhere by the pros). 

Without further ado, the modes of transportation ranked by their number of mentions in Dylan's five plus decades of songwriting, added up using's lyric search:

Trains: 39
Ships and boats: 33
Cars:  17 (including two Fords, two Cadillacs and one Buick)
Trucks: 10 
Airplanes: 6
Horseback riding: 6
Buses: 3
Horse-drawn vehicles: 3
Motorcycles: 2
Streetcars: 2
Subways: 2
Taxis: 1
Bicycles: 1
Monorails: 0

...and walking: 128

Is Dylan a walking man at heart?  He's certainly no couch potato:  constant, almost compulsive walking appears in many songs, especially those on more recent albums.  Despite the relative scarcity of mentions of personal automobiles (13% of all non-walking mentions), one looking for a pro-urban bent in Dylan's lyrics is likely to find more of a mixed bag: although negative characterizations frequently accompany mentions of cities in general, specific urban settings come off memorably well.

Sunday, May 22, 2011

Common Sense on Street Design

The Scottish Government has recently put out a policy statement on street design which represents a major step forward for the cause of narrow streets. Although the authors can't resist including a few suggested street layouts, the key change here is the rejection of the very idea of standardized street widths, which may seem like a minor point but which in fact is a repudiation of the 170-year history of government-mandated street dimensions in Great Britain:

"Width between buildings is a key dimension and needs to be considered in relation to function and aesthetics. There are no fixed rules on street widths but account should be taken of the variety of activities taking place in the street and of the scale of the buildings on either side. . . . Rigid standards on street widths should be avoided and new streets should be laid out with consideration given to the relationship between scale and the nature of the space created."
On designing for pedestrians:

"Walking is the most sustainable form of transport. Streets should be designed, not only to allow for walking, but to actively encourage it to take place. The propensity to walk is influenced not only by distance, but also by the quality of the walking experience. All streets should offer a pleasant walking experience."
On the economic utility of aesthetics in design:
"Places need to look good and work well in the long term. Design costs are only a small percentage of the overall costs, but it is the quality of the design that makes the difference in creating places that will stand the test of time. Well-designed places last longer and are easier to maintain, thus the costs of the design element are repaid over time. . . . The long term success of places can be as dependent on visual appeal as durability. The quality of the design and its appropriateness to an area can have a significant effect on the extent to which a place is liked and well-used."

One wonders how these ideas will play out on the ground, but this seems to me like a promising sign given the source of the document.

Saturday, May 21, 2011

Did Zoning Ever Conserve Property Values?

Over at Recivilization, which has a lot of fascinating content in non-blog format, there's the following nugget under the entry for zoning reform:
"Zoning's purpose was supposed to be preserving investments and neighborhoods, and yet over 70 years our massively zoned cities have seen the greatest wave of decay in urban history. There is no evidence, from anywhere, that zoning has given any declining neighborhood an extra minute of time before its doom arrives.
Let's think back for a moment to the purposes which justified the spatial separation of uses and densities in the earliest zoning codes.  These are listed on pages six and seven of the 1926 Standard State Zoning Enabling Act, including this entry on conservation of value:
"Such [zoning] regulations shall be made with reasonable consideration, among other things, to the character of the district and its particular suitability for particular uses, and with a view to conserving the value of buildings* . . . .(*Footnote: 'Conserving the value of buildings': It should be noted that zoning is not intended to enhance the value of buildings but to conserve that value -- that is, to prevent depreciation of values such as come in 'blighted districts,' for instance -- but it is to encourage the most appropriate use of land.)"
In the Euclid v. Ambler decision, Justice Sutherland attempted to justify zoning's exclusion of high-density residential uses from low-density residential areas:
"With particular reference to apartment houses, it is pointed out that the development of detached house sections is greatly retarded by the coming of apartment houses, which has sometimes resulted in destroying the entire section for private house purposes; that in such sections very often the apartment house is a mere parasite, constructed in order to take advantage of the open spaces and attractive surroundings created by the residential character of the district.  Moreover, the coming of one apartment house is followed by others . . . ."
The arrival of "apartment houses" in a neighborhood, of course, typically signifies an increase in land values in that neighborhood.  Sutherland is describing the ordinary process of urbanization, proceeding according to the highest and best use for each parcel of land as demand and value increase.  The new residents of the apartment building may sometimes be of lower economic status, on average, than the individual owner of the home that was replaced, but collectively, the economic productivity of the land (in the form of rental income and/or property taxes) has dramatically increased.  Homeowners may object to the presence of the new building, or possibly the presence of its residents, but they are nonetheless the beneficiaries of the increased land values should they decide to sell. 

This also addresses the argument that zoning provides a reassurance for investors: since an appearance of new or denser uses in a neighborhood indicates investment and is usually associated with increasing values, not falling values, what good do the exclusionary codes actually do to secure profit?  If a residential area desires to maintain its form, at least for a while, the option of temporary deed restrictions always remains.

In the absence of zoning, unchanging form is the mark of a stagnant or declining area.  When a neighborhood's land values fall, new investment, and therefore new buildings, will be rare or nonexistent.  In this scenario, single-family homes may "filter down" to lower income populations, but this will not involve any change in the physical form or residential use of the house -- the things that zoning governs.  When demand falls so far that rental income fails to cover basic upkeep, homes may be boarded up or abandoned altogether, or become victims of arson.  Again, zoning will be useless here.  The vacant landscape of portions of inner Detroit has retained its vestigial low-density residential zoning, which the 800-page Detroit zoning code dutifully recites is "designed to stabilize and protect the essential characteristics of the district," even after virtually all the structures once present have been burned, demolished or abandoned.

A regulation which prohibits the construction of multifamily dwellings, or the subdivision of land for additional single family homes, can limit an increase in land values, but can do little or nothing to prevent the decline in the second scenario.  The justification for zoning might have been more accurately put this way:  "It should be noted that zoning is not intended to depreciate the value of buildings but to constrain that value -- that is, to prevent appreciation of values such as come in 'urban districts,' for instance."  

The negative effects of artificially limiting supply, on the other hand, have been well documented: surburban sprawl as new development is pushed to the fringes, as Michael Lewyn has shown; increased property taxes leading to tax cap backlashes leading to still more exclusionary zoning; low-density neighborhoods close to downtowns making no-development "suicide pacts," as Chis Bradford describes in downtown Austin, just to name a few.

Monday, May 16, 2011

Monday Links

Nathan Lewis' latest, on traditional urbanism and ski resort villages.

A previous post here noted how the (un-calibrated) SmartCode does not permit traditionally narrow streets.  Stephen Smith now links a study showing how the DPZ-influenced Miami 21 form-based code slightly increases parking minimums over Miami's previous Euclidean zoning code. 

More from the parking files: Tampa taxpayers cover the city's parking revenue shortfalls even as the city continues to provide free and subsidized parking to its employees. 

Witold Rybczynski puts the High Line in historical context and shows why its success in New York may not be applicable to other cities.

Engineer Charles Marohn at Strong Towns blog: "If there is one thing our current financial situation should teach us about the engineering profession it is this: engineers will bankrupt us if given the chance to build our cities and towns the way they envision them."  Tons of excellent material about the economics of excessively wide streets there.

Sunday, May 15, 2011

Setbacks, Suburbs and the American Front Lawn

(A long post today, but a lot of pictures to keep it interesting, as Nathan Lewis recommends.  Good comments from him on this topic under the previous post.)

From an old Michael Pollan essay comes more support for the idea that the mandatory residential setback, featured in the previous post, owes its origins in part to the 'pastoral' landscape aesthetic championed by such men as Central Park-planner Frederick Law Olmsted:
"If any individual can be said to have invented the American lawn, it is ... Olmsted. In 1868, he received a commission to design Riverside, outside of Chicago, one of the first planned suburban communities in America. Olmsted’s design stipulated that each house be set back 30 feet from the road and it proscribed walls. ... In Riverside, each owner would maintain one or two trees and a lawn that would flow seamlessly into his neighbors’, creating the impression that all lived together in a single park."
Rare honesty in advertising.
Pollan's essay is about the historic and cultural significance of the American front lawn, not the American residential setback, but the two are in many ways inseparable.  As Pollan shows, the intent of the setback at the outset was to mandate a grassy front lawn, whether it was wanted or not  either cost, social pressure or concerns about resale value will tend to discourage creative alternatives to the bluegrass turf rolled out, for one's convenience, by the developer.  And what is the expense required to maintain all of this yard space?
While other countries routinely incorporate lawns into their detached single-family neighborhoods, it appears to be only England's colonial children — the United States, Canada, and to a somewhat lesser extent, Australia, New Zealand and a handful of other places — that have embraced the idea of large, decorative and open front lawns.

Whether this reflects a continuing market preference is unclear, since nearly all municipal zoning codes in the United States require large setbacks (see, e.g., Charlotte), depriving homeowners of any choice in the matter.  The pattern has been replicated so relentlessly across the North American continent that alternative single-family residential designs may simply have been scrubbed from the collective imagination.  Yet, if any tourist were to wander outside the historic center of any European city and into the late 20th century suburbs, an entirely different picture would emerge.  Let's explore, bearing in mind that these are all post-automobile era suburbs, most dating from after 1950:
 Suburban Paris: A 14-foot roadway and 10-foot setbacks, with garages tastefully integrated into house facades.  Setback areas have been enclosed by walls, fences or hedges, and made into functional patios ornamented by planter boxes.  A spacious and private yard lies behind the home.  There are no rear alleys.  This simple design, of which there must be hundreds of thousands of examples in Paris alone, would be illegal under most American zoning codes.

Suburban Rome: Just like Paris, but minus the sidewalks.  Setbacks are entirely occupied by patios.  Backyards are put to productive use as personal vegetable gardens with large balconies above.  There is zero turf lawn to be found.
Suburban Frankfurt: What appears to be a 1920s-era suburb, but vastly different from any American example from that time period.  Away with the setbacks altogether!   A hedge or two and some flower boxes in the windows provide all the front-facing "greenery" that is needed, at a fraction the cost and space of a front lawn. 
Suburban Prague: Seeing a pattern yet?  Small, well-maintained yards and gardens lie behind each of those houses.
BONUS - Suburban Rio De Janeiro: Myrtle trees, climbing vines, rooftop decks and trellises, embellished garages, with Cristo Redentor off in the distance.
Now for some more familiar examples:

Murfreesboro, TN: A 35-foot roadway with 40-foot setbacks.  This despite the fact that the street is a cul-de-sac and has virtually no traffic to "buffer" against. No wall, fence or hedge interrupts the Olmstedian pastoral aesthetic of the endless meadow (and would be very expensive to construct or plant at this scale, anyways). The backyard is much smaller than it might otherwise be due to the large setback. 

Great Falls, MT: Setbacks range from 25 to 40 feet here, but the low-slung ranch "snout houses" make for an even more desolate streetscape.   

Calgary, Alberta: Snout house paradise, but denser than Great Falls.  The front lawn has been reduced to a putting green why not just pull the garages to the street and let the homes have larger backyards?

Las Vegas, NV: In a desert climate, the economic wastefulness of a huge front lawn can no longer be ignored by the zoning code, and setbacks here, at around 14 feet, when combined with small backyards, make this by far the densest of any of the North American examples.  The street width requirements are unchanged, even though the ample garages and driveway spaces leave no need for on-street parking.

BONUS - New Urbanist development (King Farm, MD): Although this development is touted as a "traditionalist" alternative to typical suburbia, the setbacks here are larger than in Las Vegas, and comparable to Calgary, but with some added landscaping.  The massive street is no different than in any of the previous examples.  Further, as can be seen in an aerial view, most of these townhouses have very small or no backyards, as nearly the entire rear of the lot is taken up for alleys, parking lots and garages.  Thus, the homeowner keeps the decorative front lawn but loses the functional backyard.

If it's possible to create a single-family neighborhood of detached houses with backyards and universal car ownership while maintaining a density high enough to support urban life, the first five examples are interesting ones to consider if the addiction to the idea of the front lawn can be broken.

Wednesday, May 11, 2011

Laneways and Setbacks

Stephen Smith at Market Urbanism has been following Vancouver's experiment with the legalization of so-called "laneway houses," accessory dwelling units constructed along the lanes (or alleys, or narrow streets, depending upon one's viewpoint) frequently found running through the grid blocks of 19th and early 20th century single-family residential areas.

The potent combination of 1) minimum lot sizes and 2) mandatory front, side and rear setbacks has, in nearly all other North American cities, effectively forbidden this common sense adaptation and repurposing of neglected public ways in residential areas.  In their absence, many owners would no doubt have long ago sold off the portions of their parcels fronting on the lane, or have constructed the main dwelling closer to the street line so as to allow a larger accessory building to the rear.

The laneway law, for all its benefits, addresses neither of these fundamental constraints on the free use and alienation of land.  The laneway house that may be built cannot be deeded to a new owner and must therefore remain a rental unit (purportedly to limit increases in property values).  Further, the laneway law comes with its own new setback requirements which have caused unintended consequences in certain zoning districts

Although the history, purpose and impact of minimum lot sizes has been covered by various writers and researchers, histories of setbacks are extremely rare.  I find this a bit surprising since of all land use regulations, setbacks are arguably closest to a pure "taking" of land, in that the municipality deprives a landowner of all, or virtually all development rights to a substantial proportion of his property, with no compensation and often to no clear purpose.  If modest side and rear setbacks might be given some vaguely plausible health and safety justification, large front setbacks, in residential areas with very wide streets, are more difficult to rationalize. 

Urban Review STL, which has put together the only history of setbacks that I could find, contains a link which suggests that some setbacks, in residential areas at least, originated in a William Penn-like overreaction to disease and fire-prone conditions in the early 19th century city (although these early setbacks, implemented by restrictive covenant, generally had sunset provisions).  Today, typical zoning codes offer the following justifications:

"In general, the purpose of setbacks is to ensure that the use of a property does not infringe on the rights of neighbors, to allow room for lawns and trees, for light and sunshine in the home, for space for recreation outside the home, and to serve as filtration areas for storm water run-off." Calvert County, MD.
 Specifically addressing front setbacks:

"[The setback regulations] require larger front setbacks than side and rear setbacks to promote open, visually pleasing front yards." Portland, OR.
Is it possible, then, that this complete deprivation of an owner's right to build upon the front of his lot reflects a purely aesthetic judgment?  That judgment being, impliedly, that a patch of Kentucky bluegrass, to be forever mowed and fertilized, is more "visually pleasing" than the house that would otherwise be located there, and furthermore that his aesthetic concern overrides all competing concerns, including those of land values, efficient use of land, property rights and alternative notions of good urban design.  Vancouver architect Graham Barron, whose blog Stephen links, concludes that the setback requirements of the laneway law were similarly motivated by aesthetics, or more accurately, one particular aesthetic viewpoint.

If anyone knows of a study which has looked at the economic implications of setback laws on development patterns and/or land values I'd be very curious to read it.  Certainly it's an area which could use more discussion.

Friday, May 6, 2011

Friday Read: A History of Street Standards

During the past few weeks I've been taking advantage of the proximity of my neighborhood library to search out published articles on topics of relevance to this blog.  To follow Monday's post, I'd like to bring readers' attention to a 1995 paper by Michael Southworth and Eran Ben-Joseph on the history of street standards in urban planning, a topic which may seem arcane but which is actually a key contributing element to modern failures in urban design as well as the infrastructure crises currently facing many American cities. 

One of the interesting things to learn is that the first regulations for very wide streets long predated the automobile, and were in fact a reaction of debatable justifiability to conditions in the mid-19th century English industrial city rather than the spatial needs of the car (those regulations in turn drawing inspiration from the Baroque city planning of the previous two centuries, the aesthetic vision of which was super-human scale designed to awe and impress regardless of cost or utility, often as an expression of the political power of emerging centralized nation-states).

Another point is that the economic wastefulness of the required street standards during the modern suburban expansion was well-known and in fact strongly opposed by the homebuilders of the time, and that it was the crucial linkage of the standards to FHA mortgage qualifications, along with copycat municipal planning standards, that essentially mandated the construction of this costly, inefficient, overscaled and unsafe (due to speeding) form:
"In 1938 the FHA Technical and Land Planning divisions initiated a free review program in which prospective developers could submit preliminary plans to the FHA, whose consultants would then suggest layouts conforming to FHA. It was a powerful control mechanism, and naturally almost all subdivision developers submitted their plans for review to ensure a guaranteed mortgage. Thus, the federal government was able to exercise tremendous authority and power through the simple act of 'making an offer that could not be refused.'

"[The National Association of Home Builders] strongly opposed what it saw as excessive standards. In its 1950s Manual for Land Development the organization asked: 'Why is it that the widths of local residential roadways up to 36 and 40 feet are still advocated by some highway engineers and planning commissions?' The manual gave as the apparent reasons (1) misunderstanding of the relationship between street location, alignment width, and use; (2) adherence to the obsolete theory that every street should be designed as a traffic street; (3) insistence on continuous alignment of minor streets; and (4) disregard of economic aspects such as the cost of constructing, maintaining, and repairing from 38 to 54 percent more roadway surface than is needed .... [Emphasis added].

"The building industry's emphasis on reconsidering street standards was met with considerable reluctance by local planning agencies. The specter of substandard, street layouts along with the rise in vehicular ownership promoted a continuation of technocratic design for subdivisions."
The entire article, Street Standards and the Shaping of Suburbia, is available as a PDF here.  Lots of nice photos and diagrams included.

Monday, May 2, 2011

New Urbanism on Narrow Streets: Rhetoric and Reality

"If a street is to provide the sense of enclosure that pedestrians desire — if it is to feel like a room — then it cannot be too wide. ... This ... should come as no surprise to observant travelers, many of whom have no doubt used the words narrow and charming in the same sentence to describe the famously walkable streets of our older cities. Whether it be Montreal's Old Town, Boston's Beacon Hill, or Elfreth's Alley in Philadelphia, the narrowest streets are typically the ones most cherished by tourists and residents alike."
Andres Duany et al., Suburban Nation, p. 78.
Author's photo
Beacon Hill Street
(Acorn St.)
Circa 1820s
"Boston's most photographed byway"
Building Height: 3 stories

Roadway: 7 feet
Sidewalk: 5 feet
Landscaped Buffer: None
Setback: None

Total ROW: 12 feet*

Elfreth's Alley
Circa 1730s
"America's oldest residential street"
Building Height: 2 stories

Roadway: 6 feet
Sidewalk: 10 feet
Landscaped Buffer: None
Setback: None

Total ROW: 16 feet
Old Town Montreal Street
(Rue Saint-Paul)
Circa 1670s
"Montreal's oldest street"
Building Height: 3-6 stories

Roadway: 18 feet
Sidewalk: 12 feet
Landscaped Buffer: None
Setback: None

Total ROW: 30 feet*

*Measurements are estimates

Minimum Requirements of the Smart Code (Author: Duany, Plater-Zyberk & Company) for Urban Rights-of-Way

T4: "General Urban Zone"
Maximum Building Height: 3 stories

Minimum ROW Dimensions:
Roadbed: 18 feet
Sidewalk: 10 feet
Landscaped Buffer: 10 feet
Setback: 12 feet

Total ROW: 38 feet
Distance Between Facing Buildings: 50 feet
T5: "Urban Center"
Maximum Building Height: 5 stories

Minimum ROW Dimensions:
Roadbed: 28 feet
Sidewalk: 21 feet
Landscaped Buffer: None
Setback: 2 feet

Total ROW: 49 feet
Distance Between Facing Buildings: 51 feet

T6: "Urban Core"
Maximum Building Height: 8 stories

Minimum ROW Dimensions:
Roadbed: 36 feet
Sidewalk: 21 feet
Landscaped Buffer: None
Setback: 2 feet

Total ROW: 57 feet
Distance Between Facing Buildings: 59 feet