Planning for the connection to the IND Queens Boulevard Line began in December 1990, with the final design contract awarded in December 1992. Construction began on September 22, 1994. The remaining section from 21st Street to the Queens Boulevard Line cost $645 million. In December 2000, the 63rd Street Connector was opened for construction reroutes. The Connector came into regular use on December 16, 2001 with the rerouting of F service at all times to 63rd Street. The construction project also extended the lower level LIRR tunnel and involved a number of other elements, including the integration of ventilation plants, lowering a sewer siphon 50 feet, rehabilitation of elements of the existing line, mitigating ground water, diverting trains which continued to run through the project area and widening of the entry point to the Queens Boulevard Line to six tracks. This new tunnel connection allowed rerouting the Queens Boulevard Line trains via the 63rd Street Tunnel, which increased capacity on the heavily travelled Queens Boulevard Line. It also allowed a new local service, the V train, to run along the Sixth Avenue and Queens Boulevard lines; this service has since been discontinued and replaced with an extension of the M train.