National Docks Secondary is freight rail line within Conrail's North Jersey Shared Assets Area in Hudson County, New Jersey, used by CSX Transportation. It provides access to the national rail network to maritime, industrial, and distribution facilities at Port Jersey, the Military Ocean Terminal at Bayonne (MOTBY), and Constable Hook as well as carfloat operations at Greenville Yard. The line is an important component in the planned expansion of facilities in the Port of New York and New Jersey.