One of the great forestalled ideas in the repetoire of 20th century utopian urbanism is the skybridge. This idea of a new elevated street hierarchy was first pioneered by Ludwig Hilberseimer in his book City Plan which he published whilst teaching at the Bauhaus who went on to be director of planning in Chicago. Today is the birthday of one of the other emigres from Bauhaus to Chicago, Bertrand Goldberg who is the architect of Marina City and the sadly departed Prentice Women’s Hospital.

He also designed River City originally envisioned as a high-density site of mixed-use skyscrapers, 72-stories tall containing everything from schools to shopping centres, with the towers connected in “triads” by skybridges. It was knocked back, partly one imagines as a result of the growing fetishisation of the street, as outlined in the work of Jane Jacobs. Goldberg effectively unfolded his towers and laid them on their end, producing the sinuous low-rise structure which was eventually built.

In London there are still traces of this idea. Around the Barbican there are still remnants of the pedway which still operates as a link across the Barbican Centre from Barbican metro to Moorgate metro. The pedway came about as a means of allowing faster car routes to be built across London and keeping pedestrians separate from this. Far from being an ahistorical process, the means of justifying the separation included reference to Venice were streets and plazas are separate to the main form of transport (canal). Indeed the logic of the pedway was also partly aesthetic, as the vistas from the pedway to to the Barbican attest to.

As London’s South Bank finally gets the skyscrapers that the Festival of Britain generation imagined it would it’s clear that we won’t have the easy connection between the upper floors that their lower deck first intimated. But it its a shame. This idea of higher pedestrian linkages is one which will not completely let us alone. The Petronas towers are linked by a bridge. Steve Holl’s Linked Hybrid is another example indeed, if you look at much of Holl’s work his buildings are effectively skybridges, particularly his proposal for the Culture and Art Center of Qingdao City.