A Sensis Airport Surface Detection Equipment, Model X (ASDE-X) system is now operational at Washington Dulles International Airport, the twelfth airport for the air safety device. The FAA is deploying ASDE-X to a total of 35 of the nation’s airports. ASDE-X fuses ground surveillance data collected from a number of sources, including radar, Automatic Dependent Surveillance – Broadcast (ADS-B) and aircraft transponder multilateration, to provide air traffic controllers with a real-time, highly accurate location and identity of all aircraft and vehicles on the airport surface. Additionally, the system’s advanced conflict detection and alerting technology, Safety Logic, uses complex algorithms to detect and alert controllers to potential aircraft and vehicle incursion situations. ASDE-X assists with a more efficient traffic flow, which studies have shown has led to reduced taxi time at other ASDE-X airports. With today's high fuel cost, this not only benefits the airlines but also the environment due to reduced emissions.