The Bay Bridge that connects San Francisco to Oakland is an amazing bit of engineering; it had an upper deck for cars, a lower deck for trucks and two sets of railway tracks. It is strong enough to support the weight of 37,041 three bedroom modular homes. It is being replaced by a boring concrete bridge, with demolition planned for 2013.
Ronald Rael, Principal at Rael San Fratello Architects, has a better idea: occupy it. The idea is being compared to the High Line in New York (he even calls it the Bay Line). According to StreetsBlog , transport authorities are dismissive, suggesting that the bridge is little more than " a great permanent location of the Summer X Games."
But it is a very interesting proposal, with implications for infrastructure around the world.
Imagine housing, recreational and cultural facilities connected to a continuous, lushly planted, green strip, floating above the water - an aerial garden, as the cities newest park through which you could walk and wander and enjoy the most spectacular views of the bay.
Unlike precedents like the old London Bridge, they housing would not be built on top, but hung underneath. Not only that, they would be dry-docked houseboats that could be lowered down to the water.
The upper deck would be left for agriculture and recreation.
...A linear park with bicycle and pedestrian access, housing and cultural activities, such as theaters, commerce and museums, as well as 1.92 miles of bicycle lanes, sporting facilities, such as tennis courts, climbing walls, squash courts, and skate parks in addition to orchards, gardens and meadows, that are easily accessible and interconnected to the larger Bay Area.
The housing units would be prefabricated and use heat pumps chilled by water from the Bay.
High Line, New York, Image by Matthew McDermott
My first thought upon seeing this project in Streetsblog was that where we once had the Bilbao Effect, where every second-string town would build a starchitect-designed museum to attract attention, now we have the High Line Effect, where every old bridge gets a proposal for a park. But this is not the case; it is a serious proposal.
Many of the bridges that have been abandoned are largely former railroad bridges--a testament to the decline of rail as a means of freight and passenger transportation. As rail bridges, the structures have the capacity to support tremendous structural loads. This proposal seeks to repurpose abandoned and closed bridges as sites of potential for parks, cultural centers and housing.
Rael lists other locations where bridge conversions might take place, ranging from the Florida keys to Ottawa. It is an imaginative repurposing of great engineering for people, not cars. More in SF Streets Blog; download PDF of proposal here
UPDATE: Commenters are noting that the bridge is not suitable for housing because it is seismically unfit. Ronald Rael writes in the PDF report:
The initial proposal for the eastern span involved the construction of substantial concrete pylons to replace or supplement the existing supports at a cost of $200 million. It was originally thought that a replacement bridge would be a less expensive alternative, costing only a few hundred million more, however the most recent estimates put the price tag on the current bridge replacement at $6.2 billion.
On the financial pro forma, page 9 of the report, he budgets $200 million for "additional seismic reinforcement of the bay bridge."
Other bridges on the boards:
Proposal For London Bridge Has Solar Power, Vertical Farm
Toronto Architect Proposes Greenwrapping Elevated Highway