Chicago O'Hare Rail Transportation
For rail transportation from Chicago O'Hare Airport to downtown Chicago, you have two options: The El's CTA Blue Line or the Metra.
The El is Chicago's mass transit system, one of the only remaining elevated train systems in the world. The El's Blue Line goes straight to a station in O'Hare Airport, which is located under the Bus and Shuttle Center. As with other El trains, it runs continuously 24 hours a day, every day. Depending on the time of day, your wait at this station can be as short as six minutes or as long as 30 minutes. Normally trail transportation to downtown Chicago from O'Hare using the El takes 45 minutes.
The station is easily accessible from Terminals 1, 2 and 3. There are moving walkways and you can enjoy the nice trip through the undulating lightscapes designed by Helmut Jahn. If you are coming from the international terminal (Terminal 5), you will need to take the ATS tram.
If you are parked in one of the economy parking lots, the North Central line of Metra has a station next to the remote parking lot Lot F, which can provide you with rail transportation to downtown Chicago. The Metra train takes only 30 minutes to arrive at Union Station in the Loop. Metra's North Central rail service, however, can be infrequent and doesn't operate on weekends.