Question: The Airport Transit System (ATS) is an automated people mover system at Chicago O'Hare International Airport that was built by Mécanique Aviation Traction and began its operation when?
Sentence (from "Skytrain (Miami International Airport)"): The system, which opened in 2010 as part of an expansion of Concourse D, can transport passengers from end to end of the mile long concourse in five minutes.
Relevant evidence: No