 The Second Avenue Subway 's infrastructure also includes a connection to the BMT Broadway Line , utilizing an existing connection via the 63rd Street Line as part of phase 1 . The Q service will operate northward from 57th Street – Seventh Avenue , curving east under Central Park on the 63rd Street Line . The Q train would stop at Lexington Avenue – 63rd Street with a cross @-@ platform interchange to the F train before merging with the Second Avenue Line at 64th Street . Thus , after Phase 4 is completed , the residents of Spanish Harlem and the Upper East Side will have direct mass transit service down both Second Avenue and Broadway ( via transfer ) to the Financial District , and across the Manhattan Bridge to Brooklyn via the Q train . 
