The two tracks that run the full length of the connection begin as a continuation of the IND Sixth Avenue Line express tracks east of Broadway–Lafayette Street. These tracks include the line's only station, Grand Street, and connections to the two northern tracks over the Manhattan Bridge. The IND Sixth Avenue Line express tracks formerly continued east, ending slightly east of the Second Avenue station, and were planned to extend into Brooklyn and beyond as part of a never-built major system expansion called the IND Second System. Those tracks still exist at Second Avenue station, but now connect to the local tracks west of the station.