Traffic Director / service

In the end of a big even,it’s important to help crowd evacuate from the sight.
Sometimes, people still feel disoriented though there is a suspended directing sign.
I refer to the traffic command sign , combine with the panel display, and take advantage of the UAV's flight and movement to fly around the crowd to direct traffic.
The drone’s feature is that it has four sides high-power LEDs’ screen to show the sign.
Besides, a speaker installed in the drone is used to announce the crowd the position of itself and passengers are allowed to locate themselves more precisely.