SoylentNews

sigma writes:

Wired reports that more than 4,000 OpenStreetMap volunteers mapped out 13,199 new miles of road and 110,681 buildings in Nepal following the earthquake. They quadrupled the road mileage covered and adding 30 percent more buildings within 48 hours to provide critical information about road networks, hiking trails, relief camps, footpaths, and river crossings to governments and aid organizations.

Almost all work is done remotely from satellite and GPS data, often by volunteers with little or no experience with mapping. OSM has organized similar efforts in other crises and their system is simple enough that a quick online tutorial can get the beginners started. Their efforts are then reviewed by more experienced users.

http://www.wired.com/2015/05/the-open-source-maps-that-made-rescues-in-nepal-possible/