Second Avenue station

All entrances/exits are single-wide street stairs serving both platforms via the two mezzanine areas. The western mezzanine has two exits leading to:

• NW corner of Houston Street and Second Avenue[9]
• SW corner of Houston Street and Chrystie Street[9]

The eastern mezzanine has two exits leading to:

• NW corner of Houston Street and First Avenue[9]
• SW corner of Houston Street and Allen Street[9]

The closed mezzanine area had an exit to the median of Houston Street near Forsyth Street.

There is another, unfinished mezzanine on the east side of First Avenue. This second mezzanine is accessible only through now-blocked passages past the east end of the platforms.[10] This mezzanine was built to address a subway down First Avenue, if one were to be built.

East of the station, the center tracks continue disused along Houston, but rise to an upper level and stub-end near Avenue A at bumper blocks. Near the end, these tail tracks begin to separate to create a provision for a center track which only extends about 10 or 15 feet and stops at the bulkhead at the end of the tunnel. It was planned that these tracks would continue under the East River to the South Fourth Street Line, part of a never-built system expansion.[11] These tracks east of the station were previously used for train storage but became an oft-frequented spot for the homeless due to its location near local missions and soup kitchens.[11][12] The area was cleared out in 1990, and corrugated metal walls with bumper blocks were installed just past the east end of the platforms to seal the tunnels.[13]

As part of the 1929 IND Second System, plans for the Second Avenue Subway called for the new line to run directly above the existing Second Avenue station. Room was left for the anticipated four-track right-of-way above the Sixth Avenue trackways and directly east of the entrance at Second Avenue; on the west end of the platforms, the ceiling drops.[14] Above this lower ceiling is an empty space that can fit either four trackways, two side platforms, and one island platform (similar to 34th Street–Penn Station on the IND Eighth Avenue Line)[15] or two trackways and two side platforms.[16] The trackways can be made out from the ceiling pattern from the active platforms. The mezzanine at Second Avenue, possibly intended as temporary, has doors that lead to the unused track space.[17] Crew rooms were built on most of the space prior to the introduction of the V.

The current plans for the Second Avenue Subway, made in the 2000s, will not use this space; the new Houston Street station will instead be built below the existing one, with a free transfer between them.[18][19] The decision to use a deeper alignment under Chrystie Street was made to simplify construction and lessen impact to the community.[lower-alpha 1][20][21][22][23] Second Avenue service will be tentatively provided by the T train once Phase 3 of construction is complete. When this happens, the station will become a terminal station for southbound service. There will be a double crossover north of the station.[22] However, Phase 4 of construction will extend the line south, below Houston Street, in the direction of Hanover Square.[24][25]

In addition to the current entrances, the Second Avenue Subway station will utilize a new entrance to be constructed at Second Avenue and Third Street.[26] In accordance with the Americans with Disabilities Act of 1990, the Second Avenue Subway platform will be wheelchair-accessible;[26] however, it is unknown if the Sixth Avenue Line platforms will also become accessible.