Tired of waiting for the Mexico City government to deliver on a promise to build 186 miles of bike lanes (they've managed 14), a group of residents decided to take matters into their own hands. Eighty people from local pedestrian and bike organizations built three miles of priority bike lane in eight hours. 

These bike lanes don't have legal status, and the DIYers did interact with police at one point (they just told them "we are just doing what government should be doing themselves"). Chances are probably not good that the "WikiLane" will stick around. But the organizers are trying to prove a larger point: that residents want this, and that it's not that freaking hard.

We worked for 8 hours. We painted 5 kms. We spent less than 1000 dollars. How much would it cost to actually build the bicycle infrastructure the city needs?