M5 and M55 buses

The Broadway line began at Columbus Circle. It runs east along Central Park South one block, and turned right onto Seventh Avenue. It followed Seventh to Times Square, and bore left on Broadway. It followed Broadway to Madison Square, and bore right onto Fifth Avenue. It ran on Fifth along with the Fifth/Madison Avenue Line to 8th Street. Both lines turned left onto East 8th Street (also known as St. Marks Place) east towards Broadway. At Broadway, the Broadway line turned right and terminated at the South Ferry; the Fifth/Madison Avenue Line continued to Fourth Avenue and terminated at Astor Place and Fourth Avenue.

An M55 Nova Bus RTS-06 bus at its northern terminal in Midtown.

The current M5 and M55 follow a similar route, except the M55 does not run on Broadway north of St. Marks Place after the pedestrian plazas were implemented.

The current northbound M55 route begins at South Ferry and runs uptown on Church Street and Sixth Avenue. Downtown M55 buses run along Fifth Avenue to East 8th Street, where the route cuts over to Broadway and terminates at South Ferry. The northbound M55 runs along Fifth and Sixth Avenues until 44th Street, where it terminates.[4]

The M5 starts at 31st Street between Fifth and Sixth Avenues, using Sixth Avenue northbound and Fifth Avenue southbound until it reaches Central Park South. This corridor is shared by the M1, M2, M3 and M4 routes, and Sixth Avenue with the M7. There, the M5 runs crosstown along Central Park South (West 59th Street) and uptown along Broadway from Columbus Circle to West 72nd Street, where it crosses over to the southern terminus of Riverside Drive. This Broadway section is shared by the M7 and M104, and 72nd Street is shared by the street's M72 crosstown bus route, as well as the M57. The route shifts to Riverside Drive, parallel to Broadway and runs the entire length of the street. This portion is not served by any other bus route. At 135th Street, the bus route goes back to Broadway, where it meets the M4 route, and continues up that street until Fort Washington Avenue, where the M4 shifts on that street to head to The Cloisters while the M5 continues up Broadway until the George Washington Bridge Bus Station at 178th Street.[5]

During the daytime on weekdays, all M5 buses make limited stops between 135th and 157th Streets, as well as between 72nd and 42nd Streets. M5 Limited buses serve all local stops south of 42nd Street, between 72nd and 135th Streets and north of 157th Street. When the M5 Limited is running, there is no M5 local service.[5] The M55 runs local at all times.[4]

The M2, M3, M4, M5 and M104 are based out of Manhattanville Depot, while the M1 and M7 are based out of Mother Clara Hale Depot and the M55 out of Michael J Quill Depot.

Getting on the Broadway trolley at Herald Square, 1913

Bond of the Broadway Surface Railroad Company, issued 1. July 1884

The Broadway and Seventh Avenue Railroad opened a line from Lower Manhattan to Central Park in 1864. However, south of Union Square, tracks were not allowed in Broadway due to local opposition. Thus the route began in the trackage west of City Hall, jointly owned by the Sixth Avenue Railroad and Eighth Avenue Railroad, and used the one-way pair of Church Street and West Broadway to Canal Street and Greene Street and Wooster Street to 8th Street, north of which both directions used University Place to Union Square. North of Union Square, tracks were built in Broadway to north of Times Square, where it merged with the Broadway and Seventh Avenue Railroad's other line, along Seventh Avenue, to end at Seventh Avenue and 59th Street.

On May 8, 1884, Jacob Sharp, the owner of the Broadway and Seventh Avenue Railroad, incorporated the Broadway Surface Railroad to run along Broadway from Union Square south to the Bowling Green. It opened in 1885, and was leased to the Broadway and Seventh Avenue Railroad. A cable was installed on May 1, 1893, and the Lexington Avenue Line and Broadway and Columbus Avenue Line were also operated by cable as branches. The Broadway Line was electrified with conduit in May 1901.

The Broadway and Seventh Avenue Railroad was leased by the Houston, West Street and Pavonia Ferry Railroad on June 30, 1893, and the lessee merged with the Broadway Surface Railroad and South Ferry Railroad on November 29, 1893 to form the Metropolitan Street Railway. Buses were substituted for streetcars by the New York City Omnibus Corporation on March 6, 1936, as route number 6. That company changed its name to Fifth Avenue Coach Lines in 1956; the Manhattan and Bronx Surface Transit Operating Authority took over operations in 1962.

When Broadway from 34th Street to Columbus Circle, Sixth Avenue from 34th Street to 59th Street, and Seventh Avenue from Times Square to 59th Street became one-way streets on March 10, 1957, the Broadway-Seventh Avenue route 6's northbound route was shifted to Sixth Avenue between 34th and 59th Streets.[6] When several lower Manhattan streets were converted to one-way traffic on June 3, 1962, the 6's northbound path in the area was rearranged to travel along Greenwich Street, Trinity Place and Church Street.[7] Following the one-way conversions of Sixth Avenue below 34th Street to one-way northbound, and of Broadway between 34th and 23rd Streets and between 14th and Canal Streets to one-way southbound, on November 10, 1963, the NYCO's Sixth Avenue bus (numbered 5) was discontinued and absorbed into the 6, now designated the Broadway-Seventh Avenue-Avenue of the Americas Line, and later M6.[8]

An M5 DesignLine EcoSaver IV bus in 2009 at LaGuardia Place in Greenwich Village, its terminus from 1963 to 2010; the bus has since been retired.

Meanwhile, the Fifth Avenue Coach Company had been operating its own route 5, the Fifth Avenue–Riverside Drive line, since August 5, 1900. For decades up to the 1962 MABSTOA takeover, its route largely held the same: running from 168th Street – Washington Heights to Washington Square Park, traveling through Fifth Avenue south of 57th Street, then turning onto Broadway through Columbus Circle, turning at 72nd Street towards Riverside Drive on its way to its northern terminus. The only change in the route path was following Broadway's conversion to one-way southbound between Columbus Circle and Herald Square in 1957, requiring the northbound 5 to turn at 57th Street onto Eighth Avenue en route to Columbus Circle.[9]

In the first decade following MABSTOA's 1962 takeover of all Fifth Avenue Coach and Surface Transit lines, several changes to the M5's route were made. After Washington Square Park was closed to bus traffic on September 2, 1963, its southern terminus (and that of today's M2 and M3) was moved to 8th Street west of University Place, then turning on there to 9th Street towards Fifth Avenue.[10] Next, on November 10, 1963 (the same day the NYCO's 5 was discontinued), the southern terminus of the FACCo's 5 was moved to Houston Street and West Broadway, and its route south of 8th Street extended to Broadway southbound and Sixth Avenue northbound (M2 and M3's southern terminus was moved further east to 8th Street and Fourth Avenue in the vicinity of Cooper Square as part of the same service change).[11] The rest of the 5's northbound route below 57th Street was shifted to Sixth Avenue on January 14, 1966 following Fifth Avenue's conversion to one-way southbound.[12] Then, its northern terminus was extended to 178th Street – George Washington Bridge Bus Station on January 10, 1971.[13]

Closures of Broadway in the Theater District south of 47th Street and around Herald Square in 2009 resulted in major changes to the M6's southbound service, with the northern half of the route shifting to Seventh Avenue before returning to Broadway in the vicinity of Union Square. On July 13, 2009, southbound M6 service was rerouted to run across 23rd Street instead of 14th Street to provide more consistent service.[14] On June 27, 2010, due to budget problems, the M6 was discontinued and the M5 was extended to South Ferry via Broadway to replace former M1 and M6 service south of Houston Street.[15]

In January 2016, it was proposed to split the M5 into two routes. The uptown section would continue to operate as the M5, running between Washington Heights and West 37th Street in Midtown. The downtown section would be the M55, a new route between Midtown and South Ferry.[16][17] In July, in response to public comments, the proposal was modified so the routes could have a 13-block overlap in Midtown. Under the modified proposal, the M5 would run between Washington Heights and West 31st Street near Penn Station and Herald Square; the M55 would run between West 44th Street, two blocks north of Bryant Park, and South Ferry, starting on January 8, 2017.[18] The new route would provide 88% of M5 customers to have reliable service without transferring, since many customers from both ends wanted to retain service to Midtown (the area between 34th Street and 59th Street). The M5 would continue to have limited-stop service during the daytime, while the M55 would operate local at all times.[18] Other ideas to improve reliability, which included restoring the M5 and M6 to their pre-2010 services and converting the M5 into a Select Bus Service route, were rejected. A three-legged transfer was provided to M5 and M55 customers along Fifth and Sixth Avenues.[18][19] The split M5 and M55 services began on January 8, 2017.[19]