
The M1 follows Madison Avenue all the way to East 135th Street, where it again turns left for one block, and then immediately turns right onto Fifth Avenue (becoming a two-way at this point). The M1 turns off Park Avenue South at East 25th Street for one block, and then immediately turns right onto Madison Avenue. Union Square East continues past Union Square as Park Avenue South. It continues up Centre and Lafayette Streets, then 4th Avenue to Union Square, where it changes names to Union Square East. The M1 begins its route in SoHo at the intersection of Centre Street and Grand Street. Thus, all five routes are on Fifth and Madison Avenues from 34th Street to 110th Street.

The M4 terminates and originates near 32nd Street, while the Q32 begins at Penn Station, joining Madison Avenue at 32nd Street (northbound) and leaving Fifth Avenue at 37th Street (southbound). The M1, M2, M3, and M4 all run between Midtown or Lower Manhattan and Upper Manhattan, while the Q32 runs from Midtown north along Fifth and Madison Avenues and east over the Queensboro Bridge to Jackson Heights, Queens. The routes are the successors to the New York and Harlem Railroad's Fourth and Madison Avenues Line, which began operations in 1832 as the first street railway in the world, and several lines of the Fifth Avenue Coach Company, a bus operator that started running on Fifth Avenue in 1886. Though the routes also run along other major avenues, the majority of their route is along Madison and Fifth Avenues between Greenwich Village and Harlem. The M1, M2, M3, and M4 are four local bus routes that operate the Fifth and Madison Avenues Lines – along the one-way pair of Madison and Fifth Avenues in the Manhattan borough of New York City. M101 3rd/Lexington/Amsterdam Avs/125th St Q32 (Midtown – Jackson Heights via Roosevelt Avenue)
