How is drone (UAS) traffic regulated in the US?
Regulations regarding UAVs are very restrictive in controlled airspace. Whenever a company wants to test out a UAS, they have to request a block of airspace from the FAA (or local ATC body). This block is restricted to UAS traffic. No manned aircraft are allowed in that area for the duration of the test.

Currently companies are working with the FAA to integrate UAVs into the regular airspace system. Recently, the FAA designated 6 states as test sites for the FAA to test UAVs.