Decking over freeways isn’t as lucrative as you might think — but there are alternatives

Ponte Vecchio for a new era

I-670 hides below this building in Columbus, Ohio.

Whether I’m biking down F Street and running headlong into it, or dodging its construction equipment on the infrequent occasions when I have to drive through the I-395 tunnel, it’s hard to miss Capitol Crossing — now the largest development underway within downtown Washington, DC. I knew that this was an unusual project, but it turns out that it’s incredibly unusual: the only instance of a privately financed freeway deck anywhere in the country.

The “Ponte Vecchio” example that everyone points to is The Cap at Union Station: two narrow retail buildings alongside the principal spine of Columbus, Ohio, all built on a bridge over a freeway. It is a marvelous example of a place connector, one that seamlessly unites two emerging neighborhoods to one another.

However, these caps aren’t exactly something that can be replicated everywhere, since it’s an incredibly expensive way to fix a place. The Columbus example was funded by the federal government, as a mitigation measure for widening the freeway below. Most other recent cap proposals resulted from similar mitigation measures — and thus most are parks, both because that’s what the government builds and because their relatively light weight keeps the cost of building a deck down. Klyde Warren Park in Dallas is one example; 70% of the money came from the federal and state governments.

Three things to keep in mind when evaluating a freeway cap:

2009 01 20 - 0573-0575 - Washington DC - I-395

The future site of Capitol Crossing, on a rare car-free day (Inauguration Day 2009). Photo by Bossi, via Flickr.

1. The price of the structure is only justifiable if you’re surrounded by very high-value land — namely, a high-rise, high-rent CBD of a high-cost city. This limits the situations where these caps make economic sense to premier sites. For instance, a few blocks of air rights over the Massachusetts Turnpike in Boston’s Back Bay are currently in the planning/proposal phase, having seen prior plans fall apart during the Great Recession.

Capitol Crossing’s developers paid the District $60 million for air rights and are sinking another $400 million into constructing a platform over I-395 just east of Union Station, yielding a cost per “FAR-foot” (square foot of potential development) of around $150-200. That’s substantially higher than the $75 per FAR-foot seen in recent transactions for development sites at the periphery of downtown — but comparable to the $190 per FAR-foot paid for “dirt” within downtown DC, which is pretty much extinct. The net result of this scarcity and high prices is that only the very highest value land uses, namely office and retail, are economically feasible at this development — residential just doesn’t pay enough.

(Calculation based on pre-construction cost figures and final buildout of 2.2 million square feet. Post building calculation doesn’t include demolition costs.)

The economic feasibility line might also be teased out from the RFI responses that Virginia DOT received regarding two sites over I-66 in Arlington — one at the edge of Rosslyn’s high-rise core, and another in low-rise East Falls Church (actually within Arlington County). Almost none of the responses deemed the EFC parcel economically feasible, but many of the responses indicated that the effective “land cost” for the Rosslyn parcels, including cost of construction, at nearly $100 per square foot of FAR.

Unlike private development, a park’s feasible land value is set off-market and is thus completely subjective. In a neighborhood in dire need of a park, or on an irreplaceable waterfront site, the value of a new park may indeed justify the cost of construction.

2. It’ll be much easier, and cheaper, to build a cap if the freeway is completely closed for a while — say, for a major reconstruction. Staging construction over an operating freeway is risky, dangerous, and ultimately costly. Hence, many existing freeway-lid projects, like the Prudential Center and Copley Place in Boston, were constructed before the road underneath them opened to the public. Columbus’ lid was built during an 18-month closure of I-670, for example.

Even at Capitol Crossing, the developer realized the folly of trying to keep the freeway open during construction, and proposed to close 395 entirely for 15-18 months. The closure eventually came to naught due to politics, but would have “cut in half the construction time,” according to the Post: “Building the deck requires installing about 150 caissons along the median to support a network of steel girders… installing the caissons while the highway is in use would be hazardous and disturb nearby residents.”

3. A more entrepreneurial approach that governments can take to such a project is suggested by Matthew Kiefer, who worked on an earlier iteration of the MassPike deal:

MassDOT should adjust its expectations about the revenue potential of these difficult sites to reflect economic reality. It should rely more on rent derived from the net profit of a stabilized real estate asset – percentage rent or a share of proceeds of future sales or refinancings – and less on initial land value, which can be illusory. The Commonwealth will be around for a long time to realize patient returns.

In this PPP structure, the state “speculatively” builds the platform, then executes a “ground lease” for the air rights while keeping the property under state control. This may require a more entrepreneurial attitude towards monetization than most state DOTs are willing to take, but well-located center-city land is a great long term investment. If you really believe in the quality and long-term value of the place that you’re creating, a percentage-rent ground lease is a great way to discount the rent up front but to participate in the long-term gains.

Interestingly, Brandywine Realty Trust also suggested the same net-lease arrangement in its response to VDOT.

4. There are lower-cost alternative to a full bridging project while minimizing the freeway’s footprint and impact. In many cases, the most expensive bit will be bridging the through-traffic lanes — but even sunken urban freeways usually have lots of other spaces. Embankments are usually excessive, and building platforms can be cantilevered out over their edges. Lower-traffic ramps and shoulders are easier to close temporarily for construction. Skybridges can be assembled off-site rather than in-situ, providing more connectivity across the site while minimizing closures of through lanes.

ULI sponsored a governors’ advisory panel study about another downtown Boston air rights parcel in 2012; it recommended a lighter approach than a full-on deck, with buildings surrounding the interchange and bridges over it. (Ironically, the parcel was created through the Big Dig project!)

5. Railroad air rights have also seen active development in recent years, e.g., Hudson Yards in NYC, River Point in Chicago, and 30th Street Yards in Philadelphia. However, the costs aren’t truly comparable to freeway decks: the column spacing can be much closer for railroads than for freeways, and the vehicle movements are rather more predictable.

Oops, NPS accidentally fixed the Peters Point trail crossing

Rock Creek trail crossing at Peters Point

Peters Point, which I earlier called the worst trail junction in town, was miraculously fixed for a few days.

All it took was a resurfacing project that sent cars around the useless little loop. Since the drivers were forced to slow down and pay attention, they were much more likely to notice the crosswalk and yield to pedestrians. That’s even though the temporary crosswalk was more difficult to see, and a set of warning signs were taken away.

Now that the main roadway resurfacing is complete, though, everything’s back to “normal” now. The really sharply angled ramp has been regraded, and perhaps the crosswalk will be restriped with a ladder rather than two thin lines, but I don’t expect to see compliance to ever again be quite as high.

Not that the deadly and criminal behavior by car drivers stopped, of course. This guy illegally blew through the crosswalk without stopping, slowing, or even bothering to look for the cross traffic that was inches away.

Rock Creek trail crossing at Peters Point

“Build all the new housing in downtown’s backyard” isn’t working out well for DC

Construction around Navy Yard Metro

Part three of my multi-part series about housing production in DC went live on GGWash this week. Further installments will examine the impact of so much new housing construction on how central-city neighborhood planning — and begin to examine alternative forms that new housing besides central-city high-rises.

Part 1 – DC built 13% less housing over the past decade than its own citywide plan calls for: In 2006, DC adopted a Comprehensive Plan to guide its development efforts. At the time, the District’s population had just started to perk up after six decades of decline, and the plan reasonably foresaw that growth could continue into the future. The District’s population has indeed grown substantially, but its housing stock isn’t keeping pace.

Part 2 – The lion’s share of DC’s new housing is only going in one part of the city: Over the last decade, DC has built 13% less housing than its Comprehensive Plan calls for. Of the new housing that is going up, most of it is confined to the central city even though the plan recommends only 30% go there. Meanwhile, most parts of the District are building little or no new housing.

Part 3 – Most of DC’s new housing is in high-rises, which most people can’t afford to live in
At first glance, the District’s central-city housing boom might seem to be completely benign: as long as new housing is being built, does it matter where it is? But by funneling almost all new residences into central-city high-rises, the District is all but requiring that new housing be built with only the most expensive construction techniques, on the most expensive land. Potential residents need more choices.

A few possible bike + train itineraries via Amtrak’s Capitol Limited

Harper's Ferry in October

The Capitol Limited rolls into Harpers Ferry, W.V.

The launch of roll-on/roll-off bicycle service on Amtrak’s Capitol Limited makes it much easier for bicyclists to travel the Great Allegheny Passage and C&O canal towpath. Although the train’s mileage is very similar to the trail’s, a look at the mileage charts will still come in handy when planning an expedition.

For instance, one could complete the trip over two (slightly ambitious) or three (light) weekends, rather than blocking off an entire workweek and hoping for no rain. Starting from DC, this might look like:

Capitol Limited schedule

Capitol Limited, 2015 schedule

C&O Friday
4 PM: Amtrak from DC to Cumberland; overnight. (The late departure makes it possible to get most of a workday in.)
C&O Saturday
Bike 85 miles from Cumberland to Williamsport
C&O Sunday
Bike 68 miles from Williamsport to Reston; Silver Line back

GAP Thursday
4 PM: Amtrak from DC to Pittsburgh; overnight
GAP Friday
Bike 76 miles from Pittsburgh to Ohiopyle
GAP Saturday
Bike 75 miles from Ohiopyle to Cumberland
GAP Sunday
9 AM: Amtrak from Cumberland to DC

The trip’s even easier starting from Pittsburgh, since you can roll off the early-morning Capitol Limited and have a full day of bicycling ahead. Here’s an easy-pace three-weekend schedule, involving just one weekday:

GAP (Part 1) Saturday
5 AM: Amtrak from Pittsburgh to Connellsville
Bike back to Pittsburgh (downhill)

GAP (Part 2) Saturday
5 AM: Amtrak from Pittsburgh to Connellsville
Bike 44 miles to Rockwood
GAP (Part 2) Sunday
Bike 45 miles from Rockwood to Cumberland (mostly a fantastic downhill)
7 PM: Amtrak from Cumberland to Pittsburgh

C&O Friday
5 AM: Amtrak from Pittsburgh to Cumberland, arrive 9:31 AM
Bike 60 miles to Hancock
C&O Saturday
Bike 65 miles to Harpers Ferry
C&O Sunday
Bike 59 miles to Washington DC
4 PM: Amtrak from DC to Pittsburgh

For Washingtonians, Harpers Ferry is also a gateway to a great many weekend road rides in the western hills. Begin with the 4PM ride out on a Friday, and an overnight in the old town. The next day, choose between several loop routes near Harpers Ferry, like around Antietam or South Mountain. After one more overnight (no need to carry everything), take the train back the following morning.

Or take the train out on a Friday evening and begin riding back east along the C&O, perhaps spending a night at a trailside campsite or a cabin (Lockhouse 28 and the Bald Eagle Island campsite are 10 miles downriver, bikeable before sundown during DST). Then, head up out of the valley to explore northern Loudoun or western Montgomery counties. Ultimately, either the W&OD or C&O (or even RideOn on Monday morning from Poolesville) offer a return trip into town.

Another, less complete trail links two other cities along the Capitol Limited — Pittsburgh and Cleveland. Here’s how that trip would work as a one-way.

Friday photo: Georgetown Park, in memoriam

Remnant of Georgetown Park mall

The Shops at Georgetown Park opened in 1981 with one of the most exuberant postmodern interiors in DC. Its fantastical neo-Victorian atrium, accented with the requisite brass railings and stamped ironwork, was meant as an elegant escape from the busy streets outside, filled with specialty shops catering to the carriage trade. It’s strange that its loss raised not a peep in such a preservation-obsessed neighborhood, just as postmodernism is starting to gain attention from the preservation community.

This little scrap of the old atrium railing is within a tiny elevator lobby off M Street, next to Forever 21. The elevator is apparently used for Anthropologie’s loading and for its offices, but also has stops on floors that have been abandoned. One of the mall’s skylights is also intact, above the cash/wrap at H&M.

Friday photo: Globalization and the architecture of “triple echo McMansions”

Zilicun fields

Teardowns have recently been making the news in Arcadia, the suburb of Los Angeles where my aunt and uncle have lived for many years. Chris Hawthorne, the architectural critic for the LA Times, wrote that the new mansions are a curious simulacrum of grandiose European houses, carrying on a tradition as old as Southern California itself:

Yet to dismiss [the mansions] as mere eyesores would be to miss a larger story about immigration and architecture in Southern California in an age of globalization. The houses Tong and Chan design represent a triple echo. First, European architectural styles were widely copied in American suburbia, producing thousands of so-called McMansions. Then those styles began appearing in Chinese subdivisions, many of them designed and built by American firms… Their architecture is reassuring to Chinese buyers not just because it suggests American suburban plenty. It also reminds them of newly built and highly sought-after residential architecture on the outskirts of Shanghai, Beijing and Guangzhou…

In the late 1870s, Elias “Lucky” Baldwin, the city’s founder and one of Southern California’s great land barons, hired architect Arthur A. Bennett to design a guest cottage for his sprawling ranch. Bennett’s eclectic design mixed the English Queen Anne and American “stick” styles with elements of Swiss chalet architecture and references to Moorish landmarks and Chinese pagodas. The budget for the house, now part of the Los Angeles County Arboretum, was vast, making it a cottage in name only. With its high ceilings and exterior dripping with filigree, it is as much the product of eclectic architectural influence — and showy new money —- as even the flashiest Arcadia houses by Tong and Chan.

This description brought to mind the most curious buildings that I saw in China, the “diaolou” of Kaiping — the county my father (and his cousin in Arcadia) hails from. Like Arcadia’s new mansions, they look fantastically out of scale, and their mish-mash of architectural revivals certainly don’t match any classical notions of Good Architecture. But sometimes, globetrotting capital manifests itself in less-than-serious ways, and today the diaolou are considered global treasures. From their UNESCO World Heritage Site designation:

covered porch

The main towers, with their settings and through their flamboyant display of wealth, are a type of building that reflects the significant role played by émigré Kaiping people in the development of several countries in South Asia, Australasia, and North America, during the late 19th and early 20th centuries, and the continuing links between the Kaiping community and Chinese communities in these parts of the world.

The big difference between fin-de-siecle Kaiping and 21st-century Arcadia, though, is zoning. America might be “a free country” in many respects, but not when it comes to building houses, as a recent LA Times article by Frank Shyong reveals.

In yet another display of what Mike Davis called “slow-growth Know-Nothingism,” Anglos are using their superior access to the machinery of zoning and local elections to write into law their feelings about “those” people — in particular, changing the zoning code to severely restrict new houses. The people who vote today get to write laws affecting the people who will live there tomorrow, without even knowing or caring who they’ll be.

I used to live in another American neighborhood that’s filled with ostentatious mansions built by immigrants who earned their keep in questionable trades. These days, of course, those buildings are considered local treasures. I’m glad that the Yankee settlers who lived lived there in the 1870s and 1880s, farming and building simple cottages, didn’t have zoning — and thus couldn’t legislate into the built environment their sublimated panic about immigration and social change.

Friday photo: Build in town, not edge towns, to cut carbon

edge town

The results are definitively in: when it comes to cutting carbon pollution from new development, location is far and away the most important factor. Even bad infill development will easily beat even the best greenfield design in terms of avoiding car trips — the single most climate-damaging activity in most Americans’ daily lives.

Kaid Benfield illustrates the point by contrasting the VMT per capita within some of the best suburban and urban neighborhood designs of recent years. Grounding his analysis in research, he writes:

[L]ocation is by far the most significant indicator of how much driving typically takes place to and from a given neighborhood. This is because of something called “destination accessibility”: outlying locations have fewer jobs, shopping opportunities, schools and other typical trip destinations within easy reach than do more central locations, causing average driving distances to be longer. (It is also generally easier in more central locations to substitute transit and walking for what would otherwise be driving trips, but such “mode shifts” are statistically less significant to vehicle miles traveled than are driving trip distances.) As a result, carbon emissions from outlying locations, per person and per household, tend to be higher – typically a lot higher – than those from closer-in locations.

It takes a lot of effort to create new “connected, complete communities” from scratch, since a “complete community” depends upon a myriad of services. When the first household arrives in an incomplete “edge town” (like Kitts Creek, shown above), they may be able to walk to other houses and some services. New services won’t arrive until there’s sufficient population to support them — and in many cases, rely upon people living even further out. Contrast that with a new house within an existing “complete community,” which already has all of that community’s services at their doorstep, from day one.

I’ll note that mode shift is less statistically significant because, outside of a few urban cores where destinations are so close by that walking is enjoyable and driving a pain, driving accounts for a substantial majority of Americans’ trips. That makes development within those few urban cores that much more important, in the scheme of shifting Americans away from automobility.

Thus, the most effective land use tool that urban planners have to address the global warming crisis — and at minimal public cost, to boot — is to make infill development easier.

Applied on a global scale (or even at a citywide scale), the potential is vast: 2014’s New Climate Economy report estimated that “compact, transit-oriented cities” could keep 1.8 billion tons (CO2 equivalent) of global warming pollution out of the air annually by 2050. That’s equivalent to decarbonizing the entire US transportation sector, or the economies of Russia or India.