8 (New York City Subway service)

8 was a designation given to several services of the New York City Subway. It was first used by the Brooklyn–Manhattan Transit Corporation for their Astoria Line from 1917 until 1949. Then, the ex-Interborough Rapid Transit Company (IRT) Third Avenue El used the designation for six years, between 1967 and 1973.

The 8 label was first used for the Astoria Line, which opened on February 1, 1917, as an extension of the Queensboro Line (now part of the Flushing line) from Queensboro Plaza. The Corona Line (now also part of the Flushing Line) had already been built as another branch from Queensboro Plaza; when the Astoria Line opened half the trains ran to each terminal. At the time, the Queensboro Line ended on the other side of the Steinway Tunnel at Grand Central.

Tracks opened over the Queensboro Bridge on July 23, 1917, allowing elevated trains of the IRT Second Avenue Line to operate to Queensborough Plaza and then over either the Astoria or Corona line. Once this link opened, all elevated trains went to Astoria, and all subway trains to Corona, but this was modified by 1923, with both divisions running on each line. On March 22, 1926, the Queensborough Line (and Astoria service) was extended west to Fifth Avenue, and it was completed west to Times Square on March 14, 1927.

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