Here's a look at what you need to know about the Chicago Transit Authority. Chicago's rapid transit system is the second largest public transportation system in the United States, serving Chicago and 35 suburbs.
The rail system is referred to as the "L" because most of its rail lines are elevated above the city streets.
About: On any weekday 1.7 million passengers take Chicago Transit Authority, CTA, (buses and the "L").
There are 1,781 buses, 129 routes and 11,493 posted bus stops, serving 306.02 million passengers per year.
There are 1,200 "L" cars, eight different routes, and 145 train stations, serving 210.85 million passengers per year.
The rapid transit system provides transportation to both of Chicago's major airports, O'Hare and Midway.
The subway/underground system services downtown only. The elevated trains service both downtown and everywhere else.
History: June 6, 1892 - The first elevated railway, the Chicago and South Side Rapid Transit Company, opens in Chicago, and goes from Congress St. to 39th St.
October 17, 1943 - The State Street subway opens downtown, the first subway line in the city, all previous had been above ground.
April 12, 1945 - The State of Illinois creates the Chicago Transit Authority, CTA, to operate a transportation system in metro Chicago and Cook County.
October 1, 1947 - CTA by legislative authority, take control of all "L" and bus service in the city.
February 25, 1951 - The Dearborn Street subway opens, the second downtown subway station.
November 5, 1956 - One train slams into the rear of another, killing eight, and injuring 200. The coroner recommends signals at all train stops.
June 22, 1958 - The Congress line opens in the median of the Congress Street Expressway, now the Eisenhower Expressway.
February 4, 1977 - Four train cars fall 20 ft to the street, eleven people die, more than 180 hurt, when a motorman ignores the signals to stop and rear-ends another train.
February 27, 1983 - The first portion of the "L" line to O'Hare opens. It is completely in service by September 3, 1984.
April 13, 1992 - A part of the tunnel under the Chicago River collapses closing the State Street station for 18 days and the Dearborn station for 24, due to flooding.
1993 - The Red and Green lines are formed after rerouting.
1993 - The Orange/Midway line opens, extending travel to Chicago's Midway airport.
October 2, 1994 - All routes officially have color designations: Red Line (Howard-Dan Ryan), Blue Line (O'Hare-Forest Park-54/Cermak), Orange Line (Midway), Brown Line (Ravenswood), Purple Line (Evanston), Green Line (Lake-Ashland/63-East 63rd), and Yellow Line (Skokie Swift).
August 18, 1997 - Fare cards are first used.
April 27, 1998 - 27 bus routes are cut to save an estimated $8.5 million annually.
June 1, 1999 - Use of tokens is discontinued.
March 25, 2000 - Mirrors, monitors, and automated voices replace the last conductors used on the "L".
June 25, 2006 - The Pink L line opens, operating between 54th/Cermak and downtown. This line connects the suburbs of Berwyn and Cicero to downtown Chicago.