<P> In the vicinity of Terminals 1 - 3 and the parking lots A-C, there is an on - site airport hotel operated by Hilton Hotels & Resorts . </P> <P> O'Hare has four numbered passenger terminals with nine lettered concourses and a total of 182 gates . Two or more additional terminal buildings are envisioned; there is the possibility of a large terminal complex for the west side of the field, with access from I - 90 and / or the Elgin - O'Hare Expressway, if the runway reconfiguration is completed and passenger numbers require additional terminals . </P> <P> With the exception of flights from destinations with U.S. Customs and Border Protection preclearance, all inbound international flights arrive at Terminal 5, as the other terminals do not have screening facilities . Several carriers, such as American, Iberia, Lufthansa and United, with outbound international flights depart from Terminals 1 and 3 . This arrangement requires that passengers disembark at Terminal 5 and then, crews tow the empty plane to another terminal for boarding . This is done, in part to make connections for passengers transferring from domestic flights to international flights easier, since while Terminals 1, 2, and 3 allow airside connections, Terminal 5 is separated from the other terminals by a set of taxiways that cross over the airport's access road, requiring passengers to exit security, ride the Airport Transit System, then reclear security in either direction . </P> <P> Terminal 1 is used for United Airlines flights, including all mainline flights and some United Express operations, as well as flights for Star Alliance partners Lufthansa and All Nippon Airways . Terminal 1 has 50 gates on two concourses: </P>

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