Washington-Dulles International Airport, whose centerpiece is Eero Saarinen’s landmark Main Terminal, has implemented an Automated People Mover (APM) Airport Train System as part of its current overall development program. The APM System connects the Main Terminal to Tier 1 as well as KPF’s future 42-gate, domestic and international Tier 2 Midfield Concourses. The train system is necessary to meet the projected future passenger traffic at the airport. This new system will replace most of the fleet of Mobile Lounges, which have been in ongoing service since 1962 as part of Saarinen’s original master plan implementation.The station was resolved as a totality, in which architectural, engineering, and construction considerations were integrated within a singular vision. The sloping walls and ceilings together define a singular space, with secondary elements arranged to fulfill specific functions. The overall architectural effect is legibility.Passenger movement is direct and intuitive. On the platform level, automated trains allow passengers to exit to the side platforms, and board from the center platform. Stairs, escalators, and elevators, all oriented towards the future Tier 2, connect the platform to the mezzanine level while moving passengers towards their final destination. Upon the completion of the future Tier 2 Concourse and additional sets of escalators, arriving and exiting passengers will move in a straight, linear manner with minimum congestion.Interior finishes consist of epoxy terrazzo floors, ceramic tile walls, and ceilings of light-weight brushed aluminum panels. Glass elements include custom railings and wall cladding on the escalator trusses and elevator towers. The light and somewhat reflective quality of the glass and texture and subtle coloration of the wall tiles contribute to the station’s architectural quality, serving to reflect artificial and natural light.The new Tier 2 Station is primarily a sub-grade concrete structure whose only elements above grade include airshafts, elevator hoistways, and egress stairs designed in conjunction with the Midfield Concourse. The north part of the station will be located directly under the concourse, while the south part of the station is located directly below aircraft parking. A stand-alone temporary central plant will serve the station until the Tier 2 Concourse mechanical systems come online.