 As reported in the Chicago Sun Times, this innovative transit system combines the elements of an L train, a bus, and a monorail, offering driverless rides across the airport. This new people mover, officially known as the Airport Transit System, or ATS, was a $127 million investment designed to enhance passenger convenience and efficiency. With inflatable rubber tires on an elevated track, the ATS ensured a quiet and swift journey between O'Hare's remote parking lots and the main airport terminal.