Chicago Midway is Chicago's 2nd major airport behind O'Hare. Midway was the principal airport for Chicago until the 1962 opening of O'Hare. From 1962 until the late 1970s it was only sporadically used until the arrival of Midway Airlines. Southwest began service in 1985, becoming Midway's #1 carrier following the 1991 shutdown of Midway Airlines. Since then, Midway has become Southwest's number one station. Midway is also served by Delta, Frontier, Southwest merger partner Air Tran, and Toronto based Porter Air. During the early 2000s, discount carrier ATA had major operations here until it wound down service in an arrangement with Southwest in 2007 before shutting down in 2008. In 1993, The Chicago Transit Authority launched an orange line elevated train to downtown. Midway has 43 gates on 3 concourse with A&B being home to the dominant Soutwest and B being used by other airlines. In 2001, a new ticketing and baggage hall was built on the opposite site of Cicero Avenue from the original terminal and current concourse. Passengers use a bridge over Cicero to get to their gates. In contrast to O'Hare, Chicago Midway International Airport ranked third amongst large airports in the nation for "Best On-Time Arrival Rates" in June 2007.