The Archigram Archival Project is an excellent collection of projects and concepts that were done between the ’60s and mid-’70s.
“The Archigram Archival Project makes the work of the seminal architectural group Archigram available free online for public viewing and academic study. The project was run by EXP, an architectural research group at the University of Westminster. It was funded by the Arts and Humanities Research Council and made possible by the members of Archigram and their heirs, who retain copyright of all images” These contained, ‘nomadic’ urban spaces are reminiscent of Minneapolis’ skyway system. The problem with these types of environments is the loss of outdoor pedestrian communities. Maybe a bicycle-oriented urban design would get more people outdoors.