The Milwaukee–Dearborn subway is an underground section of the Chicago "L" system in The Loop, Chicago, Illinois. It is 3.85 mi (6.20 km) long and forms
branch, 9 in the Milwaukee–Dearborn subway and 13 on the O'Hare branch). At about 27 miles, it is the longest line on the Chicago "L" system and second busiest
Chicago Department of Transportation. Mass transit in much of the Chicago metropolitan area is managed through the Regional Transportation Authority (RTA)
is an 11.2 mi (18.0 km) rapid transit line in Chicago, run by the ChicagoTransitAuthority (CTA) as part of the Chicago "L" system. It is the CTA's newest