 M15 (New York City bus)

The First and Second Avenues Line, also known as the Second Avenue Line, is a bus line in Manhattan, New York City, running mostly along Second Avenue (and northbound on First Avenue since 1951) from Lower Manhattan to East Harlem.Originally a streetcar line along Second Avenue, it is now the M15 bus route, the second busiest bus route in the city (behind the ) and the busiest in Manhattan, with an annual ridership of over 15.5 million.