 The plans for the Second Avenue Subway involve digging 8 @.@ 5 miles ( 13 @.@ 7 km ) of new tunnel from 125th Street in Harlem south to Hanover Square , which is located in the Financial District of Lower Manhattan . During Phase 1 , the initial phase , the line was to begin at the intersection of Second Avenue and 96th Street , running south to join the BMT Broadway Line via the existing , but rarely used , BMT 63rd Street Line . Phase I stations will be located at 96th Street , 86th Street and 72nd Street . The Q service will be routed to 96th Street . The Q service will initially have a rush @-@ hour service frequency of 7 @.@ 5 to 10 trains per hour , or one train every 8 to 6 minutes in each direction ; by contrast , the IRT Lexington Avenue Line 's express tracks ( 4 5 trains ) have an estimated rush @-@ hour frequency of 30 trains per hour , or one train approximately every 2 minutes in each direction . 
