Elevated Bike Lane System Proposed for London

http://www.treehugger.com/bikes/elevated-bike-lane-system-proposed-london.html

Another nice animation. Like many people landscape architect Sam Martain gave up cycling in London as too dangerous and proposed this. 

B1 Veloway, Melbourne - YouTube

B1 Veloway, Melbourne - YouTube:

 http://youtu.be/nk8rJ2XBAwQ
Another nice proposal - following a railway track ( if segregated ) is a lovely way to get the right gradient and lack of path crossings.