You're welcome ExCon90, I was happy to have found it. I also liked the way it said, "the best passenger train which ran on the west side of Manhattan," taking pains NOT to add, "also the ONLY passenger train which ran on the west side!" Did you notice the phrase, "Good-bye Dolly?" Recall the hit Broadway play in the 1960s, "Hello Dolly?" Hmmm.
Back in 1916-1917 when the City of New York and New York Central were trying to come to an agreement on how best to get the West Side tracks off Tenth and Eleventh Avenues and relocate them to a grade-separated right-of-way, one stipulation the city insisted on was the continuation of passenger train service, to which Central agreed. In principle anyway. There were various civic groups and west side politicians who were insisting Central should provide expanded passenger service on the west side. Luckily for the railroad, the City of New York never seemed too interested in that, and none of that was ever put into any of the agreements. Obviously when the final West Side Plan was agreed upon in 1929 the city accepted that the passenger service would not be continued.
I went over to the W. 72nd Street overpass in April 1991 on the first morning Amtrak began running on the West Side Line. I was too late to see the first train; I think I saw the third (and there were half a dozen other people there too). Then I went for a ride. When we emerged from Penn Station onto the old right-of-way above W. 34th Street I felt almost as if I was dreaming!