Posts by Daniel Nairn

Roads

The Variety of American Grids

by Daniel Nairn   •   May 31, 2010 9:54 am

I wanted a nerdy planning-related poster for my wall (other than the periodic table of city planning), so I made one this week. I scoured Google Earth and measured that quintessentially American grid in about a hundred downtowns around the country.

Of course, there are variations in block proportions within downtowns, but I tried to pick cities that had more uniformity than average to come up with a single prototype. (Washington, DC has very little uniformity.)

History

The physical evolution of Blagden Alley-Naylor Court

by Daniel Nairn   •   March 29, 2010 10:25 am

Blagden Alley-Naylor Court is a designated historic district in the Shaw neighborhood, contained between O and M Streets and 9th and 10th Streets. What makes these blocks significant are the alleys that remain almost perfectly intact in their original 1865 alignment.

Many homes were built on alleys throughout the city in the late 19th century, particularly to house an influx of African American residents. Living conditions were difficult, and most of the alleys had been cleared of residential use before the city's 1934 Alley Dwelling Elimination Act.

Using historic survey maps, I've reconstructed the blocks around Blagden Alley-Naylor Court to observe how the alleys were formed and used. Click on any of the images to see in full size.

The 1861 model is based off of the Boschke survey, carried out between 1857 and 1859. This is probably how the blocks looked immediately before the alleys were installed. Some of the structures were built right up against the street frontage, but many more were simply scattered haphazardly in the interior. Since the blocks of the L'Enfant plan are quite large, measuring roughly 500x500 feet, more access was obviously needed to allow for orderly development. As far as I can tell, none of these buildings are currently in existence, at least not in any way resembling their original form.

Development

Slow and steady creates Virginia's Urban Development Areas

by Daniel Nairn   •   January 22, 2010 12:56 pm

Over the last couple of years the state government of Virginia has been rolling out a land use planning category for localities known as Urban Development Areas (UDAs), where higher density development can be concentrated.

The concept started off slowly in 2007 with HB 3202 as an advisory element to be placed in the Comprehensive Plans of "high growth" localities, but UDAs have gradually been weaved into everything from stormwater regulations to street design requirements over the last year.

The Development and Land Use Tools Subcommittee, known as the Athey-Vogel group, last week released a proposal for stronger UDAs and a loan fund to sweeten the pot. Considering the media has pretty much ignored this process (I can't find any story, actually), it seems like a worthwhile endeavor to pay attention to where this initiative may be going.

Development

Two (very different) planned towns in Maryland

by Daniel Nairn   •   January 6, 2010 12:24 pm

Passing through the D.C. metro area after New Year's, we decided to visit two classic planned communities in the Maryland suburbs: Greenbelt and Kentlands.

Both were planned and built from the ground up and both contain around 2,000 households. Otherwise, they could not be more different.

One was entirely created by the federal government, the other by private developers. One was born in the depth of the Great Depression, the other during boom years of the American economy. One has a current average home sale price of around $160,000, the other $800,000. One is exclusively modernist in style, the other highly traditional both in planning and architecture.

Anyone who seeks to pigeonhole planning into one ideological camp or the other may want to take a look at these two very different models. While there are certainly arguments to be made either for or against each of these, it seems pretty clear to me that they fit into different economic niches and lifestyle preferences. The overall metro area is that much richer for having both of them.

Transit

Virginia rail service has successful first day

by Daniel Nairn   •   October 2, 2009 9:35 am

Yesterday, I rode the first intercity passenger rail service the Commonwealth of Virginia has ever funded. The train arrived promptly at the station in Charlottesville this morning, and headed on its way to Union Station. A decent-sized crowd boarded with me, and the local media were there to film the event. Passing through the small town of Orange, not yet a stop along the route, an older couple waved to us from their porch. The last time a new service was launched in Virginia was 1956.

Both this line from Lynchburg to DC and another from Richmond to DC, which will start on December 15, were approved by the Commonwealth Board of Transportation as three-year demonstration projects. If ridership figures are there (51,000 annually), this could be a game-changer for intercity transit in Virginia. During a ceremonial "Whistle Stop Tour" along the route yesterday, Governor Tim Kaine suggested that Roanoke may be next. The residents there are already getting excited.

Rail advocates have been fighting for this service for many years. Meredith Richards, president of Virginians for High Speed Rail and Piedmont Rail Coalition, has, by all accounts, led this charge. Not only is the service expected to take 1.4 million cars off the highways each year, it provides a vital economic link between Virginia cities and the nation's capital. I would add that enhancing rail service could only help to facilitate compact development around the rail stations along the route, as well as feed into and strengthen the D.C. metro system.

The service did suffer a setback last spring when the schedule was pushed later by a couple of hours. Many people were concerned that the difference between a 9:20 and an 11:20 arrival would deter commuters. It seems that the very profitable freight rail operations still take precedence over passengers when it comes to scheduling. When I talked to Meredith Richards about this, she was grateful that the Virginia Department of Rail and Public Transit had initiated a new service at all, but she was also concerned that the scheduling would not demonstrate the full ridership potential of the corridor.

This trip is perfectly convenient for me. I needed to be in Crystal City for the American Collegiate Schools of Planning conference from Thursday through Sunday. I live a 10 minute walk from the Charlottesville Amtrak station, and the hotel for the conference is right on the Metro Yellow Line, just three stops up from the Alexandria Amtrak station. The whole trip is cheaper, faster, and less of a hassle than driving. The man next to me says it shaved three hours off his usual trip to Boston, which had previously required a bus and a layover. I doubt we're complete outliers. As more and more people realize that their transportation options have just expanded, the momentum for rail travel in Virginia will surely continue to build.

I made the trip door-to-door within three hours. Not bad for the first day.

Bicycling

What if we counted people like we count vehicles?

by Daniel Nairn   •   September 24, 2009 10:22 am

Of all of the disparities between different transportation modes, one of the most important and least talked about is the disparity of information. Right now in American cities we have an enormous and expanding set of knowledge about how cars and trucks move, yet we know almost nothing quantitatively about how pedestrians and bicyclists use the infrastructure.

Cameras and in-ground road sensors are placed in strategic locations along roadways, constantly streaming to gather very rich data on vehicular traffic patterns. Here are all of DC's. The data is processed and collected to, among other things, make future projections. Eventually a decision-maker, perhaps recalling that sinking feeling we've all felt after failing an exam, sees a thick red line on the map—Level of Service F—looming in the future and knows this is very serious indeed. Something happens.

Because pedestrian and bicycle infrastructure lacks this precision of data, or any data at all in most cases, there is little scientific support for funding it. Technocrats see such projects as window-dressing on the business of real mobility, nice features that the Federal Highway Administration lumps together with museums and lighthouse renovations as "transportation enhancements." Most people reading this blog see things differently. But how do we prove it? And how do we efficiently allocate bicycle and pedestrian infrastructure investments where they will be most effective? Useful knowledge simply requires more data.

Public Spaces

Constructive stormwater management proposals emerge in Virginia

by Daniel Nairn   •   August 25, 2009 2:22 pm

When the Virginia Department of Conservation and Recreation (DCR) unveiled proposals for amended stormwater regulations this past spring, some observers were concerned that the stricter regulations would make denser development, and redevelopment of existing sites in particular, more expensive relative to low-density development. This would likely not bode well for smart growth, nor would sparser development ultimately lead to better water quality for the whole Chesapeake Bay watershed.

To DCR's credit, a period of robust public comment on the proposals was held until Friday, and all 407 online comments can be viewed on their website. As a result of this participation, several environmental groups and experts of various disciplines have offered constructive policy solutions to address this unintended consequence, while still maintaining the original intent of the regulation.

Here's a few creative ideas that have emerged:

David Slutzky, Chairman of the Albemarle County Board of Supervisors and a former senior environmental policy adviser in the Clinton white house, believes that the regulations, as they stand, will "most certainly lead to de-densification of new development activities in the [Urban Development Areas] UDAs." In order to fairly distribute the responsibility of reducing runoff, he would like to offer developers a series of options to meet the new requirements.

His most interesting idea is a tax-credit fund used to reward redevelopment projects (former industrial sites, for example) that go the extra length to reduce impervious surfaces or implement stormwater reduction Best Management Practices (BMPs) on site. The fund would be paid into by developers, at a rate set by the water impacts of their projects, and disbursed by DCR to the most competitive redevelopments of the year. This would seem fair, considering redevelopers are the only ones currently being asked to shoulder the burden of achieving net improvements to the watershed without being offered help with the costs involved. Carrots and sticks belong together.

Senator Creigh Deeds, who also happens to be the Democratic Party's candidate for Governor, has his own suggestions for avoiding the promotion of more sprawl, something he believes the current proposals might lead to. If stormwater requirements were measured by the house, rather than by the acre, then Deeds believes that higher density developments would perform better in the evaluation. Deeds is also in favor of a tax credit incentive for stormwater management in urban redevelopment.

The Southern Environmental Law Center simply suggests reducing the requirements for redevelopment from "return to forested levels" to "return to pre-development levels." This reduction would only apply to redevelopment within UDAs designated by the locality. While only a minor change, the SELC hopes it will be enough to still encourage compact development.

The Rappahannock River Basin Commission wants to see the "refinement of off-site alternatives" for compact developments. There are provisions in the DCR proposal for developers to purchase credits from other sites in lieu of meeting the requirements on site, but many have pointed out that an efficient transfer system has not been adequately explained yet. The statement from the Lord Fairfax Soil and Water Conservation District doesn't exactly spell out an answer, but they do suggest that the regulations "should be examined, clarified, and written to encourage urban redevelopment and smart growth."

All of these recommendations are encouraging to see, and DCR will likely take many of them into account in their final revisions. Environmentalist groups have evolved, as evidenced by these comments, from seeing their mission solely in terms of making all land as much like wilderness as possible to recognizing that the urban and the rural need to be treated differently to reach optimal levels of environmental protection.

As Kaid Benfield has written,

"the best thing to do environmentally is to manage and shape [growth] so that a good quality of life is maintained with the least environmental harm. This is fundamentally about per capita, or per household, thinking: how can we shape the new development so that it has the least impact per increment of growth?

This is the essence of smart growth. But it also represents a fairly radical departure from traditional environmental thinking (and much of environmental law), which focuses our attention not on per capita impacts but on particular pieces of land, parcel-by-parcel."

It looks as if many in Virginia are making this transition.

Retail

"Bank deserts" harm underserved communities

by Daniel Nairn   •   August 18, 2009 11:16 am

The term "food desert," a neighborhood without sufficient access to healthy foods, has quickly become an accepted phrase for anyone thinking about cities. Now the Federal Deposit Insurance Corp. has released data suggesting that the same phenomenon has been occurring with newly opened bank branches. They've been able to identity a pretty strong positive correlation between the siting of new banks and the median income of an area. Out of more than 10,000 branches opened in the last five years, only 1 out of 10 were placed in an urban location with high minority populations.

So what? Given all of the toxic asset and bank failure mayhem being announced everyday, it may seem that folks are better off if Citigroup doesn't want to set up shop on their block. However, without a physical bank within easy reach, many low-income residents have had no choice but to pay higher fees for check-cashing services, often businesses that also wave fast money in their face with unreasonable interest rates attached. The same demographic that may be more likely to receive a physical paycheck and less likely to have access to internet banking happen to be the ones who are being underserved.

I see this every day. There's a "payday loan" operation and two "Quik Mart"-type convenience stores right across the street from me. Why is it that expensive low-quality food and expensive low-quality financial services cluster together? It's probably because of a lack of market options due to spatial barriers and transportation infrastructure deficiencies. We can have a conversation about personal responsibility to eat well and make sound financial decisions, but as this data and my own experiences indicate, these decisions too often run into the simple barriers of geography.

Public Spaces

Stormwater management should work with, not against, Smart Growth

by Daniel Nairn   •   July 8, 2009 10:56 am

Virginia is updating statewide stormwater regulations. A draft is open for public comment until August 21, 2009. Some people are concerned that the stricter caps on nutrient loads, as currently written, will promote low-density development and ultimately hurt the water quality and quantity of runoff in the Chesapeake Bay watershed.

Here's a simple but realistic hypothetical scenario. Developer A wants to develop 100 dwelling units on 1,000 acres of land, and developer B wants to develop 100 dwelling units on 10 acres of land. Developer A will only need to cover 10% of her large site with impervious surface, while developer B will need to cover 70% of her small site with impervious surface. Developer A assumes that 100% of residents will use an automobile for transportation, while Developer B assumes 50% will primarily walk or use transit. Therefore, Developer A's project will require twice as many parking spaces and approximately twice as much road width in the region, but will accommodate most of the parking off-site.

Under the stormwater regulations being proposed, Developer A will likely score an A+ with a pass to move forward, while Developer B will fail. This is because the standards are determined, site-by-site, on a per acre basis and not a per unit basis. Developer B may have the option of purchasing off-site water quality improvements or implementing a set of BMPs to offset the damage she is incurring, but she takes a hard look at her balance sheet and decides to join developer A as a business partner. What benefited the individual acres of the sites in question clearly was an overall loss for the watershed as a whole.

And considering opportunity costs makes the situation even dicier. What if these developers bypass infill redevelopment of an industrial site for a more compliant and cheaper greenfield development? (Stormwater controls will generally be more expensive for redevelopment than new development). Now you have impervious surfaces in two places, instead of one.

The economic market analysis, conducted for the Department of Conservation and Recreation by a Virginia Tech professor, bears this out in more detail.

Based on this site-by-site method, low density developments would produce less estimated phosphorus runoff than medium or high density areas. Very low density developments (1 dwelling unit per 3 to 5 acres) would unlikely face any water quality control requirements. Yet, on a watershed basis, low-density ("sprawl") development increases dependence on auto transport (thus increasing emissions and roadway impervious surfaces). Highly impervious areas accompanied by dense population settlement can produce net water quality improvements, independent of whether stormwater controls are implemented ... Higher phosphorous control costs in high density developments create financial disincentives that may work at cross purposes with larger watershed objectives.

I'm no hydrologist. Most of the science and bureaucratic mechanisms behind this policy are pretty bewildering, and I don't really have the time to try to figure them out. Furthermore, I thought it might be safe to assume that as glaring a potential problem as this is, somebody in the state offices must be working to sort it out. Then I read this comment from a member of the Technical Advisory Committee that helped craft the policy:

Stormwater management seeks to replicate the water quality and quantity benefits that are provided by a natural, undeveloped landscape. Development that contains more natural landscape (e.g. rural dev.) will consequently find it less costly to comply. This is not a fault of the stormwater management regulation; it is a natural consequence of the hydrologic cycle.

In other words: That's life. Deal with it. He went on,

Stormwater codes should be judged on how well they manage runoff quantity and quality, not how well they do or don't control growth ... Smart growth codes should be judged by how well they control sprawl.

This is where the trouble lies. Sometimes genuinely smart and well-intentioned people err by focusing intently on the piece of the puzzle they have been commissioned to solve, thereby missing the larger system within which their problem is embedded. It's the classic widen-the-freeway-to-reduce-congestion scenario. It may solve the technical problem at hand, but it exacerbates the real problem.

The fact is that stormwater management and Smart Growth have everything to do with each other. Treating them separately and pitting one against the other is a losing game for both water quality and growth of development.

This was demonstrated pretty convincingly by a 2006 EPA report. Here are the three scenarios proposed by the study:

They put this model to empirical tests and mined numerous other studies to back up their conclusions. Once again, the crux of difference:

The results indicate when runoff is measured by the acre, limiting density does produce less stormwater runoff when compared to the higher-density scenarios. However, when measured by the house, higher densities produce less stormwater runoff.

They show that this is the lapse in logic that lead so many regulatory agencies to assume that sprawl is good for controlling stormwater runoff:

Many communities assume that low-density development automatically protects water resources. This study has shown that this assumption is flawed and that pursuit of low-density development can in fact be counterproductive, contributing to high rates of land conversion and stormwater runoff and missing opportunities to preserve valuable land within watersheds.

And this report focuses exclusively on quantity of water runoff. If you look at the issue of quality and factor in the introduction of pollutants such as motor fuels, de-icing chemicals, vehicular exhaust, lawn fertilizers and pesticides, faulty septic systems, and more into the water supply, the case against promoting low-density development grows and grows.

Let's not strike out on this one.

Crossposted at Discovering Urbanism.