I grew up a block away from the confluence of the LIRR, PRR(PC) and the Myrtle avenue el train yard near Fresh Pond Road. So when did the LIRR freight service become NY Atlantic? I only ask since when I left in 1979 seems now to be a lifetime ago.
On a similar question, I frequently travel I-78 from PA to Newark NJ. In the Bloomsbury area there is a double track overpass that I only see CSX trains on, yet on CSX’s site their map shows no such line. I don’t like being the confused one. I much prefer to do the confusing.
I’m not very great with that area, but I’ve driven past many times (I have relatives in the Morristown/Whippany area) and they could be tracks belonging to Conrail Shared Assets. This is a terminal railroad serving both CSX and NS in areas that were ex-Conrail and were needed by both CSX and NS when they split Conrail in 1999.