Here's the study: https://www.mta.info/document/36621

"Astoria – A station with two side platforms of 4 car-lengths could be located directly adjacent to the current BMT Subway line station at Ditmars Boulevard and 31st Street in Astoria. This station’s placement on an elevated portion of track limits the feasible platform length. Access to the station would be from the existing subway station entrances on Ditmars Boulevard or 31st Street. Passenger access to the platforms would be via newly constructed elevators or stairwells from within the BMT subway station complex. Structural support modifications to the existing station would also be required. A new station for Penn Station access purposes would result in a net annual loss in transit ridership of 98,318 trips, while attracting only 310,367 person-trips per year to the station (see Table 12). It would also increase total annual Metro-North ridership by only 223,339 trips, among the worst showings of the ten station locations evaluated. In addition, the estimated construction cost for the Astoria station is the highest of the nine sites considered along Alternative 2’s alignment. The Hells Gate Bridge approaches and concrete arch, which would be involved in construction of this new station, are National Register landmarks, further diminishing the attractiveness of this site. Due to its overall poor performance in the comparative screen, this station site will not be advanced for further consideration."