 From Sullivan northwards, the extension runs entirely along the Haverhill Line right of way, which substantially lowered land acquisition difficulties before construction.An additional segment to the elevated Malden Center, which includes a platform for the Haverhill Line, opened on December 27, 1975.After debate about how far the extension would run, it was decided that it would terminate at the north edge of development in Malden, rather than continue through a narrow pass between the Middlesex Fells and the Pine Banks and into the less-dense suburbs of Melrose and Wakefield.