The building coincides with the MTA’s East Side Access project, and station improvements due to One Vanderbilt’s construction will provide extra capacity for over 65,000 new passengers going into the New York City Subway at Grand Central–42nd Street. The improvements include an underground connection between Grand Central Terminal and One Vanderbilt; new mezzanines and exits for the subway station, including an entrance directly to the 42nd Street Shuttle platforms; three new stairways to each of the Lexington Avenue Line platforms; reconfiguration of columns supporting the nearby Grand Hyatt New York hotel; and a commuter waiting room in the building’s lobby, resulting in additional capacity for 4,000 to 6,000 more subway passengers per hour. ICC is providing quality management on the station enhancement portion of the project.
These improvements will cost over $200 million. In 2015, SL Green gave $220 million toward the building’s construction, of which two-thirds of the money will be used for station redesign, the largest private investment to date to the New York City Subway system. As part of the station construction, 40% of the basement of the Grand Hyatt New York will be destroyed in order to make room for the expansion of the subway mezzanine, as well as two new subway entrances in One Vanderbilt itself.