The Chicago Transit Authority (CTA) is a public transit agency in Chicago, Illinois, United States and one of the three service boards of the Northern Illinois Transit Authority (NITA). It operates the Chicago "L" rapid transit system and CTA bus services.
The CTA was established as an independent governmental agency by the Metropolitan Transportation Act passed by the Illinois General Assembly on April 12, 1945. It started operations on October 1, 1947, upon the purchase and combination of the transportation assets of the Chicago Rapid Transit Company and the Chicago Surface Lines streetcar system. In 1952, CTA purchased the assets of the Chicago Motor Coach Company, resulting in a fully unified system. As of 2026, the CTA is one of the three service boards overseen by the Northern Illinois Transit Authority (NITA), along with Metra commuter rail and Pace Suburban Bus.
In 2025, the system had a ridership of 319,160,900, or about 1,101,600 per weekday as of the second quarter of 2026.
The CTA was formed through the Metropolitan Transportation Act passed by the Illinois General Assembly on April 12, 1945. It started operations on October 1, 1947, upon the purchase and combination of the transportation assets of the Chicago Rapid Transit Company and the Chicago Surface Lines streetcar system. Over the next few years CTA modernized the "L", replacing wooden cars with new steel ones and closing lightly used branch lines and stations, many of which had been spaced only a quarter-mile apart.
In 1952, CTA purchased the assets of the Chicago Motor Coach Company, which was under the control of Yellow Cab Company founder John D. Hertz, resulting in a fully unified system. By 1960, the CTA replaced all of its streetcars with buses. The CTA system for decades also included a large number of trolley bus routes, and in the 1950s had one of the largest such networks in the country, but trolley bus service was phased out between the late 1960s and 1973.
On March 20, 2026, CTA sued the Trump administration for freezing $3.1 billion in rapid transit rail project funding. The funding was previously approved for upgrading and expansion of the Chicago "L"
On September 1, 2026, CTA's parent agency, the former Regional Transportation Authority (RTA), was replaced by the new Northern Illinois Transit Authority (NITA).
The Chicago Transit Authority provides service in Chicago and surrounding suburbs of Forest Park, Evanston, Skokie, Oak Park, Summit, Cicero, Berwyn, North Riverside, Rosemont, Evergreen Park, Oak Lawn, Park Ridge, Harwood Heights, Norridge, Lincolnwood, and Wilmette. The CTA operates 24 hours each day and on an average weekday provides over 950,000 rides on buses and trains.
The Chicago "L" is the rapid transit system serving the city. It is the third-busiest rapid transit system in the United States. As of January 2025, the "L" has a fleet of 1,560 train cars serving over eight routes and 226 miles (364 km) of track. Its trains provide an average of 471,547 customer trips each weekday and serve 146 stations in Chicago and seven suburbs. The majority of train stations CTA operates have elevators or ramps to provide access for customers with disabilities. All trains are accessible, either through fully level boarding or a ramp to bridge the 3-4in height gap.
The rolling stock of the CTA consists of four series of electric multiple unit rail cars that includes the last rail cars built by the Budd Company and rail cars built by Morrison-Knudsen, Bombardier, and CRRC. Manufacturers of former rolling stock include Boeing-Vertol, Pullman Car Company, St. Louis Car Company, and Cincinnati Car Company.
The 5000-series was built by Bombardier from 2009 to 2015. Ten (10) prototypes of the 5000-series were received in 2009, and entered passenger testing in April 2010, with 396 more ordered once tests were completed. On July 20, 2011, CTA announced the order of 300 more rail cars, bringing the total ordered to 706 at a cost of about US$1 billion. The more recent 7000-series is being built by CRRC Sifang America, with delivery of production cars beginning in 2022.
The CTA is the primary operator of buses in the Chicago area. As of January 2025, it has approximately 2,000 buses that operate over 127 routes traveling along 1,516 miles (2,440 km). Buses provide about 638,212 passenger trips each weekday and serve more than 10,000 posted bus stops.
As of December 2025, CTA's fleet of buses is mostly dominated by Nova Bus Nova Bus LFS. Formerly, New Flyer's D40LF dominated the fleet which replaced buses that were built in 1991 and 1995. In 2014, CTA ordered 400 new buses from Nova. The number increased to 425 after it exercised an option. The CTA exercised another option for an additional twenty-five buses, from Nova Bus. Nova Bus delivered an additional 600 new buses which replaced the remainder of the older Nova buses that were delivered between 2000 and 2002, in addition to starting the retirement of New Flyer D40LF buses delivered between 2006 and 2009.
In 2014, the CTA received their first electric buses from New Flyer, making the CTA the first major U.S. transit agency to use the new wave of electric buses as part of a regular service.
As mandated by the Americans with Disabilities Act of 1990 for all transit operators in the U.S., all CTA buses are accessible, with a ramp on every bus available for use.
The governing body of the CTA is the Chicago Transit Board, consisting of seven members. Four members are appointed by the mayor of Chicago, while the other three are appointed by the governor of Illinois. Each appointment requires approval from the other party. Board members serve seven-year terms, staggered to reduce sudden shifts in policy. The board chooses a General Manager to oversee day-to-day operations; the position was renamed executive director in 1976 and has been known as president since March 1992.
The Chicago Transit Board is advised by the ADA Advisory Committee and Citizens Advisory Board, which are composed of Chicago-area residents chosen by the board.
After the September 11 attacks, CTA announced its "If you See Something, Say Something" campaign. CTA has also installed a security camera network, and a system to send real time images from cameras in buses directly to emergency responders.