Construction of the Second Avenue Subway is surging ahead at what will become the future 86th Street station — part of the $4.5 billion first phase that is expected to be completed in December 2016. The first phase runs from 105th Street and Second Avenue to 63rd Street and Third Avenue. Officials estimate it will carry between 200,000 and 225,000 riders each day. The Second Avenue Subway promises to ease the commute on the East Side of Manhattan, from Harlem to the Financial District.