Why can’t we have one??

Since last July, London has had a (small) network of bike “superhighways” connecting various suburbs to the city center.  The CS7, for one, runs 8.5 miles (!!) from the southern surburb of Merton into London proper.  At completion, the superhighway system will consist of 12 routes radiating out to London’s surroundings.  The lanes are five feet wide and accommodate traffic in both directions.  Why can’t we have just one of these?  Forget sharing the street with motorists, can we just build some elevated bike overpasses like pedestrians have in Vegas?  (Read more here)