South of 120th Street, the line will utilize a tunnel section built during the 1970s, located between 110th Street and 120th Street. This section will have tracks and other essential equipment installed, like that of the rest of the line. Cut-and-cover will be used to connect the existing tunnel section to the bored section to the north (at 120th Street) and to the portion of the line already in operation to the south (at 105th Street) to maximize the use of the tunnel sections built in the 1970s. A bellmouth will be constructed to allow for a future extension to the Bronx at 118th Street. The storage tracks west of the 125th Street station would replace the storage tracks north of the 96th Street station, which would then be used in revenue service as part of Phase 2.