What is the main way to move between terminals at O'Hare Airport?

The main way is the Airport Transit System (ATS). This free, automated train connects Terminals 1, 2, 3, and 5 with the rental car center (MMF).

How can I transfer from Terminal 5 without going through security again at O'Hare?

Use the Terminal Transfer Bus (TTB). It operates airside (within the secure zone) but only during limited hours: daily from 11:30 am to 9:30 pm. Stops are at Terminal 1 (Gate B1), Terminal 3 (Gates G17 and K20), and Terminal 5 (Gate M13).

Can I walk between terminals at Chicago O'Hare?

Yes, Terminals 1, 2, and 3 are connected via pedestrian walkways. Walking is sometimes faster than waiting for the ATS, especially if you are not carrying much luggage. It's a good alternative to save time between these three terminals.

What is the biggest issue with the ATS at O'Hare?

The biggest issue is its low frequency at night. Although the Airport Transit System (ATS) operates 24/7, wait times can be long and frustrating during off-peak hours, unlike the 3–5 minute frequency during the day.

What is the Terminal Transfer Bus (TTB) and when does it operate?

The TTB is a bus that connects the secure (airside) areas of Terminal 5 with Terminals 1 and 3, allowing passengers to avoid exiting and re-clearing TSA security. It operates daily from 11:30 am to 9:30 pm with a frequency of every 15 minutes. Outside these hours, you must exit security and use the ATS.

Is the Airport Transit System (ATS) free at O'Hare?

Yes, the ATS is completely free. It runs a 3-mile (4.8 km) loop in about 10 minutes, connecting Terminals 1, 2, 3, and 5 with the Multi-Modal Facility (MMF) for rental cars, Pace buses, Metra trains, and parking.

What is the travel tip for transferring between Terminals 1, 2, and 3 at O'Hare?

If you are traveling between Terminals 1, 2, and 3 without much luggage, walking may be faster than waiting for the ATS. If you use the ATS at night, expect longer waits compared to daytime service.

Terminal Connections at O'Hare Airport

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Navigating between O'Hare's terminals can be challenging, but services like the Terminal Transfer Bus (TTB) and the Airport Transit System (ATS) make it easier. These free transportation options efficiently connect the airport's different areas, although passengers should anticipate possible delays, especially during peak hours.

Quick Questions about Connections at O'Hare

What is the main way to move between all terminals? The Airport Transit System (ATS) train. It's a free automated train that connects Terminals 1, 2, 3, 5, and the car rental center (MMF).
How do I connect from Terminal 5 without going through security again? Use the Terminal Transfer Bus (TTB). It's an airside (secure area) bus, but it has a limited schedule (11:30 am - 9:30 pm).
Can I walk between terminals? Yes, Terminals 1, 2, and 3 are connected by pedestrian walkways. Sometimes it's faster than waiting for the ATS, especially if you don't have a lot of luggage.
What is the biggest issue with the ATS? Its low frequency at night. Although it operates 24/7, waits can be long outside peak hours.
What if my connection is international-to-domestic? Neither the TTB nor the ATS directly help you: you must first go through immigration and customs at Terminal 5, collect your luggage, and re-check it. Only then can you use the ATS to get to your next terminal.

Terminal Transfer Bus (TTB)

The Terminal Transfer Bus (TTB) connects the secure areas of Terminal 5 with Terminals 1 and 3 (boarding pass required). This service is especially useful for passengers with connecting flights at Terminal 5 gates M1-M40, as it allows them to avoid exiting and going through security again.

User experience:

The TTB is generally reliable and considered a great shortcut. However, its schedule is limited. Outside its operating hours (9:30 pm to 11:30 am), passengers must exit the secure area to board the ATS train, which means going through TSA security again at the destination terminal. Reviews also warn of possible crowding and delays during peak hours.

Traveler tip: To avoid missing your connection, always check if the TTB service is operating within your travel time and plan extra time in case of delays, especially during busier periods.

Schedule and Stops

Frequency: every 15 minutes
Hours: daily from 11:30 am to 9:30 pm
Stops: Terminal 1 (Gate C18B), Terminal 3 (Gates G17 and K20), and Terminal 5 (Gate M13).

Airport Transit System (ATS)

The Airport Transit System (ATS) is an automated transportation system covering a 3-mile (4.8 km) circuit, with a total travel time of just 10 minutes. It is a free service connecting Terminals 1, 2, 3, and 5 with key areas such as the Multi-Modal Facility (MMF) for rental cars, Pace buses, Metra services, and parking areas.

User experience:

Although many passengers appreciate the convenience and frequency of the ATS during the day, reviews point out occasional service interruptions for maintenance, which forces the use of slower replacement buses. The main complaint is the low frequency at night, with waits that can be long and frustrating.

Traveler tip: If you're traveling between Terminals 1, 2, and 3 without much luggage, walking is sometimes faster. If you're using the ATS at night, keep in mind that the wait will be longer than during the day.

Schedule and Frequency

Hours: operates 24 hours a day.
Frequency: every 3-5 minutes during peak hours.

Pros and cons of terminal connections at O'Hare

Pros: both services are free; the ATS operates 24 hours a day; the TTB allows connections to Terminal 5 without going through security again; walking between Terminals 1, 2, and 3 is a viable and sometimes faster alternative.

Cons: the TTB has limited hours (11:30am-9:30pm); outside those hours, connecting to Terminal 5 requires going through TSA again; the ATS reduces its frequency at night; occasional service interruptions for maintenance may force the use of slower replacement buses.