The Multilevel Metropolis

[M II A II R II K]

The Multilevel Metropolis


May 2016

BY JENNIFER YOOS AND VINCENT JAMES

Read More: https://placesjournal.org/article/mu...urban-skyways/

The grade-separated pedestrian systems built in the 20th century have a variety of names: skyways, skywalks, pedways, footbridges, the +15, and the Ville Souteraine. But they have one thing in common — they have radically altered the form and spatial logic of cities around the world.

- North American cities like Minneapolis, St. Paul, Des Moines, and Calgary have extensive skyway systems that parallel the original streets. Montreal and Toronto have subterranean labyrinths. Hong Kong has floating three-dimensional circuits that connect transit stations, shopping malls, office towers, and parks. And multilevel urbanisms continue to expand. In the last decade, Mumbai has relieved its crowded streets by building nearly 40 pedestrian overpassess. Yet even as such infrastructures proliferate, they receive scant critical attention, despite their fundamental role in the production of urban space.

- Early experiments in multilevel urbanism belonged to social utopians and the architectural avant-garde, the systems that were built at scale were advanced by pragmatists who embraced both the public and private spheres. As cities struggled to withstand the growing economic power of suburbs, civic leaders began to “pedestrianize” their urban centers. What better way to compete with the suburban shopping mall than to mimic its enclosed form? Cities began to connect and consolidate interior spaces through skybridges and arcades, in an effort to make downtown convenient, comfortable, safe, and climate controlled for office workers and shoppers.

- These pedestrian systems can be conceived as a “thickening” of the street level or a “delamination” of the ground plane into a second level above or below grade. This doubling, or sometimes tripling, of the street was described by urban critic Trevor Boddy in the 1980s as an “analogous city.” The spatial ambiguity created by the stacked circulation levels — which often lack suf­ficient vertical connections — can render the urban layers as fully independent realms. For that reason, skyways and tunnels are seen by many theorists as deviant or untenable urban forms.

- Nevertheless, they are attractive to city planners and business leaders for their ability to concentrate transit, commerce, and real estate value. Once established, such systems tend to expand, incrementally and informally, according to private and public development interests. What begins with a few interconnected blocks in the downtown core grows over decades into a pedestrianized, multilevel central business district. The largest networks reach an autocatalytic stage, like the 69-block Minneapolis Skyway, where future developments must be connected to be competitive. At that point, these systems have to be acknowledged as durable urban forms.

- In the 21st century, we see a new wave of interest in the skyway as architectural form. Steven Holl’s high-wire act in Beijing, the Linked Hybrid complex (2009), features bridges stretched taut between buildings, while his Vanke Center (2009) in Shenzhen links buildings and programs in an elaborate city-scaled lattice. MVRDV has proposed high-rise towers in Seoul (2011) and Shanghai (2015) that are grafted together by pixelating the building module to form a bridge of housing and public space. Urban retail complexes by Zaha Hadid Architects, Foreign Office Architects, and Future Systems weave layered bands of horizontal circulation, extending interiorized commercial space to an urban scale.

- Similar to his superblock proposals for Montreal, which integrated shopping malls and transit, Vincent Ponte’s vision for the Dallas Pedestrian Network encompassed the entire downtown. His clients were the corpora­tions that occupied the majority of the office space, including powerful oil and tech companies. The system he designed comprised one mile of overhead walk­ways and two miles of underground tunnel links, connecting a total of 36 blocks. Here, too, the network evolved into a more informal configuration, despite the comprehensive master plan. The combination of above- and below-grade connections amplified its discontinuities. Responding to the car-centric culture of Dallas, developers prioritized parking ramp connections and vertical links to surface parking lots.

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Pedestrian skyways in Hong Kong. [Photo by the authors]






St. Paul, Minnesota. [Photo by the authors]






Mumbai, India.






Steven Holl, Linked Hybrid, Beijing, China.






Allied Works, National Music Centre of Canada, Calgary, 2016.






SOM, Grand Central Station Next 100 Years, 2012. [© SOM/Crystal]






Hong Kong. [via Wikimedia Commons]