The exhibition's catalogue shows 18 bridges, mostly reasonably current although including London's Millennium Bridge as something of a golden oldie (described somewhat daftly in the catalogue as "London's only pedestrian bridge"). Only 8 of these have actually been completed, which is fairly representative of the often uncertain funding situation for new landmark bridges.
The majority of the bridges are what can only be described as iconic, and several are structurally perverse, flag-bearing representatives of post-modernist abstraction. PoMo has finally hit the bridge design world several decades after building design, and of course any such trend is inescapable. However, bridge design more than building engineering cannot avoid the expression of structural form, and when the structure is as contorted and unnecessary as in several examples here, you have to ask whether there is a better approach.
The worst offenders include the Eel Net Bridge (pictured), Liverpool's Paradise Street Footbridge, and Bristol's Mobius Bridge. These follow the "blobitecture" trend where advanced CAD geometry allows the invention, analysis and construction of increasingly abstract forms, none of them bearing any relation to optimum structural behaviour. These blob-bridges are the post-modern descendents of the thin-shell and membrane engineering of masters like Eladio Dieste, Eduardo Torroja and Jörg Schlaich, and to my taste at least, completely lack the awe-inspiring elegance and charm of their ancestors.
It looks unlikely that I'll be in London to see the exhibition before it closes, so if anyone attends, please feel free to report in the comments!