Hundreds of drones are expected to hit the Singapore skies in the near future, but many questions how they will safely fly over dense and urban areas have risen lately. Researchers have unveiled a traffic management system, which is much like the traffic laws and infrastructure cars have on roads. Named Traffic Management of Unmanned Aircraft Systems, this initiative would designate air-lanes and use virtual fences to reroute drones around restricted geographical locations.
http://i-hls.com/2017/01/uav-traffic-management-system-will-designate-urban-air-lanes/