M100 (New York City bus)

Several companies, most prominently the Metropolitan Transportation Authority (MTA), operate a number of bus routes in Manhattan, New York, United States. Many of them are the direct descendants of streetcar lines (see list of streetcar lines in Manhattan).

Presently, the New York City Transit Authority and its subsidiary Manhattan and Bronx Surface Transit Operating Authority operate most local buses in Manhattan. The Roosevelt Island Operating Corporation operates the Roosevelt Island Red Bus Service on Roosevelt Island.

The first bus company in Manhattan was the Fifth Avenue Coach Company, which began operating the Fifth Avenue Line (now the M1 route) in 1886. When New York Railways began abandoning several streetcar lines in 1919, the replacement bus routes (including the current M21 and M22 routes) were picked up by the New York City Department of Plant and Structures (DP&S). The DP&S began operating several other buses (including the current M79 and M96 routes) in 1921. All of these but the M21 were acquired by Green Bus Lines in 1933; Green transferred several of these to the Comprehensive Omnibus Corporation in 1935.

The New York City Omnibus Corporation began operating replacement routes for New York Railways lines abandoned in 1936, and acquired the remaining Green routes. They also acquired the Madison Avenue Coach Company (former New York and Harlem Railroad lines), Eighth Avenue Coach Corporation (former Eighth and Ninth Avenue Railways lines), and in 1942 the Triangle Bus Corporation (current M21 route).

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