The Airport Transit System (ATS) at O’Hare International Airport will resume round-the-clock service starting at 5 a.m. on Monday, April 18, the Chicago Department of Aviation (CDA) announced today.

The ATS is a convenient, fast, reliable, and fully-automated “people mover” at O’Hare. The transit system transports passengers between Terminals 1, 2, 3 and 5, and the Multi-Modal Facility, or MMF, home to the rental car center, Economy Parking Lot F, the Kiss ‘n’ Fly, several Pace routes, and a Metra station. 

The ATS reduces road congestion and emissions, as fewer cars and buses are needed to travel between terminals, parking lots and ground transportation facilities. Each three-car train can carry 147 passengers, with service operating every three minutes. The three-mile trip between Terminal 1 and the MMF takes only 10 minutes, with five total stops.

Shuttle buses will continue to provide 24-hour service through Sunday, May 1, as an additional option for passengers traveling between the four terminals of O’Hare and the MMF.

ATS service hours have been expanded several times since the new train system reopened to the public in November. The work to modernize and expand the ATS started in 2017 and involved integrating a completely new rail vehicle and control system on the existing track, expanding the fleet of vehicles from 15 cars to 36 cars.

Service updates for the ATS can be found at flychicago.com/ats.