An overall review of the Kuala Lumpur International Airport (KLIA) project in Malaysia is provided to compare how the design/build Track Transit System (TTS) system, an automated people mover (APM), relates to the other major design/build KLIA projects (Main Terminal, Apron and Tunnel, and Satellite A Terminal) of the total airport design and construction program. Major interfaces being managed, which are typical for any such large new airport construction program, are: (1) Main Terminal interior spaces for station and ATC room; (2) Apron and service roads; (3) Tunnel under taxiway; (4) Satellite A building station accommodations and other system rooms including Central Control, maintenance, storage, UPS, PDS, and offices; (5) Underground utility services; (6) TAMS (Total Airport Management System); and (7) Other services such as power supply. The steps in defining, controlling and managing interfaces among separate design/build contracts are discussed. This includes: (1) the process of specifying interfaces and contract provisions prior to contracting, (2) refining and coordinating the interfaces during the design phase after contracts are signed, and (3) finalizing certain interfaces under a fast-track schedule where construction of some facilities are underway before the design is complete. Formal and informal procedures followed are identified and discussed as they relate to reaching agreement amongst the parties involved, control of interfaces configurations, and the overall KLIA program schedule.