Just yesterday, Jaymi showed a guy zipping 'round town on a wire and I thought, why build all of this wire infrastructure for a zipline when you can just give the guy a bike? But Martin Angelov of Kolelinia Lab beat me to it, and instead he gives the bike a wire. Angelov's Kolelinia project creates bike lanes in the sky out of a network of wires and suspended troughs, creating a minimalist version of Velo-City.The wheels of the bike fit into a furrow, or trough that is supported on a rail, so that will be pretty stable. An attachment to the end of the handlebars keeps you connected to a safety wire, so one is unlikely to fall over.
The safety device is very clever, with a mechanism that pivots around the safety wire supports.
Velo-City: Cycle Tracks Will Abound in Utopia
While I am really fond of Chris Hardwicke's Velo-City, no doubt Martin Angelov's proposal would cost a lot less to implement, and is less intrusive on the skyline.