The Korean and U.S. governments are implementing a reciprocal "trusted traveler" program at Washington Dulles International Airport. It allows travelers from each country visiting the other to use unmanned immigration booths if they register their fingerprints and photos in advance.
Korean travelers can take advantage of the Global Entry kiosks in U.S. airports, and U.S. visitors can enjoy quick process through Smart Entry Service e-gates in Korean airports.
This will greatly reduce the time Korean travelers have to spend in immigration queues. Anybody over 17 who has a national registration card and e-passport can benefit from the agreement, but they need to register for Korea's Smart Entry Service.