http://www.tpl.org/content_documents/Ur ... raffic.pdf
Link to article (ULI, 2007) regarding highway caps and parks. The St. Louis example is in bold but gives the whole article gives some further perspective.
Nature Over Traffic
by Peter Harnik and Ben Welle
Urban radicals want automobiles banned from cities, while urban moderates can, perhaps, live with them—as long as they are not seen or heard. In European central cities, the urban radicals have the upper hand. In the United States, where moderates reign, cities are increasingly settling for a compromise—an expensive compromise—by putting freeway segments underground and covering them with parkland. Whether called lids, decks, bridges, or tunnels, there are already at least 20 highway parks across the country and at least a dozen more somewhere in the planning pipeline. As urban auto impacts become less welcome, these decks have moved from the novel, to the accepted, and, increasingly, to the expected. The sometimes considerable cost has gone from being classified “pork barrel” to being redefined as “amenity investment with high economic payback.”
Most famous is Seattle’s aptly named Freeway Park, designed by the Lawrence Halprin landscape architecture and design firm, which opened with great fanfare in 1976. But the concept actually goes back to 1939 when Robert Moses built the Franklin D. Roosevelt Expressway along Manhattan’s East River, tunneled it under the mayor’s home at Gracie Mansion, and constructed 14-acre (5.6-ha) Carl Shurz Park on top. Moses did it again in 1950, in Brooklyn, when citizens rose up against a planned expressway through the center of Brooklyn Heights. As a compromise, he added the one-third-mile-long (0.5-km-long) Brooklyn Promenade with its supreme view of lower Manhattan, remarking self-satisfiedly at the ribbon cutting, “I don’t know of anything quite like this in any city in the world.”
The latest decks have been New Jersey’s innovative highway redesigns in Trenton and Atlantic City and the still-not-completed series of Rose Kennedy Greenway parks over Boston’s massive “Big Dig.” [See “Filling the Cut,” March 2006, page 65.] In a study carried out by the Washington, D.C.–based Trust for Public Land’s Center for City Park Excellence, it was found that the average size of the nation’s freeway parks is about nine acres (3.64 ha), and that, on average, each one covers 1,620 linear feet of highway.
The Interstate Highway System, when it was conceived in the early 1950s, was designed to link but not penetrate cities. By the 1960s, however, that detail had been forgotten. Highways became the preeminent tool of urban renewal and redesign, and vast swaths of urban real estate were paved over. Waterfronts were blockaded in Portland, Cincinnati, Hartford, Cleveland, Philadelphia, and San Francisco. Nooses of concrete were tightly wound around the downtowns of Dallas and Charlotte. Trenches of noise and smog cut through Boston, Detroit, Seattle, and Atlanta. Massive elevated structures threw shadows over Miami and New Orleans. And wide strips of land were taken from large iconic parks in Los Angeles (Griffith Park), St. Louis (Forest Park), Baltimore (Druid Hill Park), and San Diego (Balboa Park).
A few downtown parks actually survived the devastation thanks to the intervention of historic preservationists, including Lytle Park in Cincinnati and the National Mall in Washington, D.C. In both cases, citizen outcry forced the highway builders to tunnel underneath the surface (although technically Lytle Park was leveled and then reconstructed three years later).
But it was not until the construction of Seattle’s brand-new Freeway Park that the “deck-the-freeway” concept began getting some serious attention. Because of the constrained, hourglass geography of Seattle, Interstate 5 (I-5) was a particularly damaging road, and the environmentally oriented populace was dismayed by the impact. “There was a large moat of traffic between downtown and historically residential First Hill neighborhood,” says David Brewster, president of the Freeway Park Neighborhood Association. But the city was lucky: not only was I-5 sunk into a deckable trough as it passed downtown, but also a former Seattle mayor, James “Dorm” Braman, had just been appointed assistant secretary of transportation for urban systems and the environment by then-president Richard Nixon. Pushed by civic leader Jim Ellis and paid for under the city’s “Forward Thrust” bond initiative, Freeway Park opened in time for the Bicentennial and garnered coast-to-coast attention. “It was a model for other cities to heal the scar that cuts right through a neighborhood,” says Brewster.
Freeway Park, while beautiful and memorable, failed on one major count: acoustics. At just five acres (2 ha), it could not completely muffle the sound of traffic, and the park experience is accompanied by a constant white noise—not obtrusive, but not minimal, either. The park also has some safety and design issues that the city is now seeking to resolve.
Phoenix’s ten-acre (4-ha) Hance Park seems to have solved the noise challenge (as has Seattle’s new, much larger Sam Smith Park). Described by the Phoenix New Times as “a rare Phoenix instance of nature over traffic—in this case, literally,” Hance Park is decked over the Papago Freeway, uniting uptown and downtown and providing a park adjacent to the city’s central library. The freeway (Interstate 10) was originally planned as an elevated bridge through downtown, but opposition by citizens and the Arizona Republic killed that idea in a 1973 ballot measure. Not until ten years later did the city finally accept a below-grade solution with the park as a key sweetener. Hance Park opened in 1992 and today is the site of a Japanese garden.
Freeway parks have also bridged the divide between cities and their waterfronts. In Duluth, Minnesota, for example, a plan to build Interstate 35 through downtown Duluth along the shoreline of Lake Superior generated intense opposition from environmentalists and historic preservationists. “The highway extension became a very polarizing issue in the city,” says former city planner Richard Loraas. In an effort at compromise, Duluth architect Kent Worley proposed covering the road with a large platform for about four city blocks. “That’s the solution,” Loraas recalls saying. Through shortening the freeway and using the resources for the covers, the idea received support from federal transportation officials and powerful Duluth Congressman John Blatnik. Ultimately, three different deck parks were built, including one that saved Duluth’s historic rose garden. “The solution cleaned up the whole stretch of land along the lake,” says Loraas.
While construction costs for deck parks can be painfully high, there is also an upside: the land itself is generally free, made available as air rights by the state transportation agency. In center-city locations, this can amount to a multimillion-dollar gift. Land near the Santa Ana Freeway by Los Angeles City Hall, for instance, goes for $2 million to $3 million an acre ($4.94 million to $7.41 million per ha). In near-downtown San Diego, by Balboa Park, an acre is worth up to $13 million ($32 million per ha).
Regardless of cost, the forces driving—and making feasible—most deck parks is the opportunity for private development and redevelopment around them. In Trenton, for instance, the New Jersey Department of Transportation spent $150 million on the new 6.5-acre (2.6-ha) Riverwalk deck over U.S. 29, linking the city to the Delaware River. In response, notes Trenton planning director Andrew Carten, “The project resulted in a significant spike in interest in and the sale prices of property. After all, would you rather look over 600 trucks barreling past every day, or a scenic park and river?” One lot, worth $120,000 before construction, was developed with six housing units that sold for $200,000 each. The existence of the park also helped attract a new 82-unit market-rate residential building.
Projects where freeways are already below grade are much more feasible than others, and there are four particularly high-prospect opportunities in major downtowns today in St. Louis, Dallas, Cincinnati, and San Diego.
In St. Louis, one of Mayor Francis Slay’s top priorities is the “three-block solution,” a plan to cover a portion of I-70 between center city
and the Gateway Arch. “We’re trying to get the annual 3 million visitors to the Arch into downtown St. Louis,” says Peter Sortino, president of the St. Louis–based Danforth Foundation, which is handling the planning. “We’re also trying to help those already downtown more easily reach the Arch and the Mississippi riverfront.” An early rough estimate put the cost at a minimum of $40 million.
Cincinnati faces the identical situation.
An interstate highway, Fort Washington Way, blocks downtown from the Ohio River and the city’s two new sports stadiums. However, there the political will has not yet solidified. Cincinnati had an opportunity to construct
a five-block-long park deck during a recent reconstruction (and road narrowing), but opted not to because of cost. As a compromise, the new Fort Washington Way was equipped with $10 million worth of steel pilings capable of supporting a future park. (Adding the park deck is estimated to cost $46 million.)
Dallas, on the other hand, is fired up about the opportunity of building a park over a stretch of the Woodall-Rodgers Freeway. The freeway separates the city’s downtown and arts district from the Uptown neighborhood, and a three-block park cover is seen as both improving the urban form and opening up new opportunities for development. An existing trolley line would run through the park and condominium towers are expected to flank it on both sides. The park’s price tag is estimated to exceed $60 million, but ardent boosters are seeking to raise one-third of that from private sources.
Downtown interests in San Diego are in the early stages of evaluating decking a few blocks of I-5 so as to link with Balboa Park. The city is in the midst of an unprecedented center-city residential construction boom, and the highway presents a major barrier for the thousands of apartment dwellers who have little access to green space.
Despite the cost of a park deck, there are numerous sources of local, state, and federal funds to cobble together, particularly if an analysis shows that associated development will generate significantly more tax revenue. One direct approach is to create a tax increment financing (TIF) district, whereby future increased tax revenue is used to pay back the costs of the deck park. (Chicago used a TIF as partial funding for Millennium Park, which was built over railroad tracks.) Other local funding sources include general public works capital funds, revenue from another form of a special tax district, or municipal bonds. (Seattle’s “Forward Thrust” bond paid 20 percent of the cost of Freeway Park.) Often, the deck superstructure is paid for by the federal government, while actual park development is financed by the city. (Phoenix, for example, spent $5 million landscaping Hance Park.)
On the federal level, several decks were built using the transportation department’s interstate construction program, but that no longer exists. At present, a state can use national highway system or surface transportation program funds (although only at the time of road construction, not as an after-the-fact retrofit). The transportation enhancement program conceivably could be used if the project provides pedestrian and bicycle facilities and landscaping and scenic beautification. In addition, while the community development block grant (CDBG) program has shrunk since Seattle used it for Freeway Park in the 1970s, it is still also available.
State transportation funding may be available, too. The Trenton project involved reconstruction of a New Jersey highway, and the state transportation department paid for it. In Duluth, the Minnesota department of transportation contributed 10 percent of the cost. Private funding also can play a role. In Cincinnati, for instance, 20 percent of the narrowing of Fort Washington Way was financed through private dollars, including $250,000 from the Cincinnati Bengals.
The real key to a successful highway park deck is the economic spin-off that is generated. With a deck costing as much as $500 per square foot ($5,380 per sq m) to build, it must be carefully justified through its potential impact as a redevelopment tool for surrounding real estate. Only then will the rate of return show both public and private funding sources the value of the investment.
Many years ago, urbanist and public intellectual Lewis Mumford said, “Forget the damned motor car and build the cities for lovers and friends.” Constructing parks over freeways does not forget the automobile, but, if done right, it offers some help to lovers and friends. That is a combination that could make political leaders happy.
Peter Harnik is director of the Center for City Park Excellence of the Trust for Public Land, and author of Inside City Parks. Ben Welle is a program assistant with the center. (A condensed version of this article was published in the January issue of Governing Magazine.)
forgot about MetroLink.
Hold on while a take a walk four blocks over and have a little chat.
