The Airport Transit System (ATS) is an automated people mover system at Chicago O'Hare International Airport. It opened on May 6, 1993. The ATS operated 24 hours a day, 7 days a week and was designed to move passengers between the airport terminals and parking facilities.
The system has been closed to passengers since January 2019 as part of a modernization plan to connect the ATS to a new multi-modal facility, and to upgrade the fleet to Bombardier Innovia APM 256 cars. No reopening date has been announced.
