The Bowling Green-South Ferry Shuttle (also Bowling Green Shuttle) was a service of the New York City Subway system between Bowling Green and the South Ferry inner loop. It operated to provide South Ferry service for IRT Lexington Avenue Line riders during hours when the 3 service did not stop at South Ferry (weekdays during the day and at first also late nights). Because the inner loop station that the shuttle used at the South Ferry station was on such a tight curve, cars used on the shuttle were equipped so that the center door of each car could be opened there, while keeping the others closed.