In 2009, the MTA and the New York City Department of Transportation (NYCDOT) identified the M14A/D, on parallel 14th Street, as a potential corridor for Phase II of SBS, the city's bus rapid transit system, as well as finalized plans to implement SBS on the M16/M34 along the also-parallel 34th Street. The crosstown bus corridors were noted for slow travel speeds. The M23 was originally not planned to be an SBS route, but in 2008, it had been part of a pilot program in which 30 articulated, redesigned SBS buses were rolled out on the M23 for some time.
