There is no demand for the Setauket spur. In the early 80s, fly ash from LILCO was shipped out. In the mid 80s, salt was shipped in. In the late 80s, a large shipment of bentonite for the Town of Smithtown was shipped in. I presume Keyspan ships the flyash by truck now. It was about 5 to 10 gons per week. Salt is no longer delivered presumably because of NYSDEC regs about covering it. To the best of my knowledge, all road salt destined for LI is shipped to Queens, and then trucked to the various highway yards.
I thought/wished that land use trends would revive Setauket. In the 80s and 90s alot of industrial waterfront in Port Jeff and elsewhere were being replaced with condos. If the stone dock were replaced with condos, rr freight traffic would increase. Nearly all stone on LI comes by barge. Prima Asphalt in Holtsville is the only major rr stone customer that I know of, and represents a small fraction of the total stone imported to LI.