People movers — automated rail systems inside airports — are still rail. Coming back to ride them later isn’t practical, so whenever I’m at an airport that has one, I ride the full line while I’m there. The ATS (Airport Transit System) at Chicago O’Hare International Airport was one of those.
ATS Overview
O’Hare’s ATS is an automated rail system connecting 5 stations over approximately 4.8 km (3 miles). Free and running 24 hours.
- Terminal 1
- Terminal 2
- Terminal 3
- Terminal 5
- Multi-Modal Facility (rental cars, parking)
Terminal 4 doesn’t exist (skipped numbering). End-to-end travel from Terminal 1 to Multi-Modal Facility takes about 10 minutes. Peak frequency is every 3–5 minutes. Top speed is approximately 80 km/h (50 mph).
Trains are 3-car sets with a capacity of 147 passengers. A major overhaul in 2021 doubled the fleet from 15 to 36 cars and added the Multi-Modal Facility extension with a new station. No gates or tickets — anyone can board.
O’Hare sometimes assigns departures and arrivals to different terminals, so the ATS is used for intra-airport transfers more often than you’d expect.
Source: Chicago Department of Aviation
Riding Record
Rode from Terminal 3 to the end of the line at Multi-Modal Facility, then back to Terminal 1. All 5 stations, full line covered.
The View
The ATS runs on an elevated guideway, giving a clear look at the airport’s back end. Runway edges, maintenance facilities, and parked aircraft pass by in quick succession. I saw a China Airlines 747 freighter taking off. Uniformed pilots were riding in the same car — the ATS is a working commute for airport staff, not just a passenger shuttle.
People Movers as Rail-Riding Targets
The ATS is a short line — about 10 minutes one way — and easy to complete. Ride from Terminal 3 to the end and back; that’s it.
That said, turning around at the terminus with no reason to be there feels slightly awkward. Every other passenger has a destination. Being the only person riding for the sake of riding is a particular kind of discomfort that only rail completionists understand.
One practical note: the ATS runs outside the security perimeter. If you’re riding it during a layover, you’ll need to exit security to board and go through screening again when you return. For connections between different terminals, you’d need to re-screen anyway. But for same-terminal connections, riding the ATS means extra security screening that you wouldn’t otherwise need — plan your time accordingly.
People Movers at Other Airports
Major U.S. airports often have multiple terminals spread over large distances, so automated rail systems are common: Dallas, Atlanta, San Francisco, Denver, Washington Dulles, Newark, among others. Outside the U.S., large airports like Singapore Changi also have them.
In Japan, Kansai International Airport’s Wing Shuttle is an equivalent system, but full-scale airport rail lines are far less common than in the United States.