Transportation Between Terminals (ATS & TTB) | Chicago O’Hare International Airport (ORD)

Transportation Between Terminals


ATS - Temporarily Closed 

The Airport Transit System (ATS) at O'Hare will return to service as soon as the system is operating safely and reliably. Substantial progress has been made during the ongoing testing, system integration, and commissioning process and the Chicago Department of Aviation (CDA) continues to work aggressively with its contractor to complete the project. 

In order to maintain a travel connection between all of O’Hare’s terminals and parking lots, the CDA will operate shuttle buses to transport passengers and employees between terminals (Terminals 1, 2, 3 and 5) and from the terminals to each economy parking lot (Lots E, G, H); the Multi-Modal Facility, where Lot F and rental cars are housed; and the Metra O’Hare Transfer station. The buses will operate continuously to ensure prompt and reliable service while the ATS is closed.

  • Buses arrive every 5-15 min
  • Bus stops are located on both the upper level and the lower level, depending on the route and terminal:
    • Buses to parking lot F and for rental cars stop on upper level.
    • Buses to all terminals and all other remote parking lots (E, G, H) stop on upper level from the domestic terminals (1,2 & 3) and lower level in Terminal 5.
  • ​Buses from the Multi Modal Facility are located on the main level
    • ​​Buses are routed to specific terminals and arrive every 5-15 min

If connecting between domestic Terminals 1, 2 & 3, you DON’T have to leave the secured side and take the shuttle buses, you can simply follow the overhead signage to guide you between all domestic terminals.

The CDA is committed to providing a quick and reliable bus shuttle service as the ATS modernization is finalized.

Look for this sign when trying to locate the Transit System.

The Airport Transit System (ATS) is a quick and convenient way to get around O'Hare International Airport.  An overall modernization to the ATS is underway to upgrade technology and enhance performance of the existing 25-year-old system. These improvements include the addition of a  larger new fleet of cars, that will double capacity of the system, providing passengers a faster and more streamlined connection throughout the airport. In the next year, the recently opened  Multi-Modal Facility (MMF)​ will incorporate an extension of the ATS to service a new train station on the second floor of the building.

An expanded and modernized ATS will benefit O'Hare travelers moving between the terminals, economy parking lots and the new MMF. 

Terminal Transfer Bus (TTB) - Service Temporarily Suspended 

TTB SERVICE HAS BEEN TEMPORARILY SUSPENEDED - TTB service takes travelers from the domestic terminals (1, 2, & 3) to Terminal 5 without having to exit security or be rescreened in Terminal 5 at the TSA​ checkpoint. Shuttles to transport passengers between all terminals and remote parking are still operating 24/7, those shuttles pick up on the Upper Level roadway (Ticketing Level). ​

The International Terminal 5 is not connected to the domestic terminals and is accessible via the Airport Transit System (ATS). If you arrive on a domestic flight and must connect to an international flight departing from Terminal 5, you have two options: 1.) you can take the ATS and pass through the security check point in Terminal 5 or 2.) you can take a Terminal Transfer Bus (TTB) from Terminals 1 and 3 to Terminal 5 and bypass the security check point in Terminal 5.

The Terminal Transfer Bus service is year round with operation hours as follows: 11:00 am - 9:00 pm.

Terminal Transfer Bus (TTB) Terminal 1 and Terminal 3 Pickup Locations

  • Gate B1 (T1)
  • Gate G17 (T3)
  • Gate K20 (T3)
  • Gate L24 (T3)

If you arrive at O'Hare on an international flight and have a connecting domestic flight, you will arrive at Terminal 5. You may only use the TTB if you have rechecked your luggage and if you have a boarding pass for your connection. Proceed through Terminal 5 security to Gate M1. If you are arriving internationally and must check-in for your connecting flight, you may not use this service.