Editing Blue Line (CTA) (section)

=== O'Hare branch ===
The '''O'Hare branch''' is the longest section of the Blue Line ({{convert|14.6|mi|km}}) and comprises both the oldest and newest segments of the entire route. The line starts at [[O'Hare International Airport]] in [[O'Hare station|an underground station]] below the airport's main parking garage, with direct pedestrian access to Terminals 1, 2 and 3. The line emerges in the median of the O'Hare main access road ([[Interstate 190 (Illinois)|Interstate 190]]) just northwest of Terminal 5, about a mile (1.6&nbsp;km) west of Mannheim Road.

The line runs in the median of [[Interstate 190 (Illinois)|Interstate 190]] east through [[Rosemont, Illinois|Rosemont]]. The line has a station at River Road in {{cta|Rosemont}}, which is also the location of the northern storage yard and served as a temporary terminal from 1983 to 1984 while the O'Hare station was being completed. The tracks then tunnel beneath the [[Kennedy Expressway]]/[[Northwest Tollway]] interchange near the [[Des Plaines River]].

The line runs in the median of the Kennedy Expressway ([[Interstate 90 in Illinois|Interstate 90]]) until a point southeast of Addison Street, making stops at {{cta|Cumberland}}, {{cta|Harlem|Blue|O'Hare}}, {{cta|Jefferson Park}}, {{cta|Montrose|Blue}}, {{cta|Irving Park|Blue}} and {{cta|Addison|Blue}}. Between Montrose and Irving Park, the line tunnels beneath an express lane exit. South of Addison Street, the line descends into a subway and turns south under Kimball Avenue. The line travels under Kimball Avenue and [[Milwaukee Avenue (Chicago)|Milwaukee Avenues]] through [[Logan Square, Chicago|Logan Square]], making stops at {{cta|Belmont|Blue}} and {{cta|Logan Square|Blue}}.

South of Logan Square, the line emerges above ground onto an elevated structure parallel to Milwaukee Avenue. This section of structure, built in 1895 as part of the Metropolitan Elevated's [[Logan Square branch]], is the oldest portion of the Blue Line, and the sole section of the line on an elevated viaduct. The three stations on this section ({{cta|California|Blue}}, {{cta|Western|Blue|O'Hare}}, and {{cta|Damen|Blue}}) are also the only three stations on the line to use side platforms instead of island platforms.