Not mentioned in the article, but I presume that's the end of the 2nd Ave subway. I already expressed my superstitious feelings about this line in an earlier comment at ET. I suppose it's not really superstition, but the fact that the city only gets around to thinking about it after a boom has been going on for a while, which means the bust can't be far off.

The first time they discussed it, the Great Depression hit. The second time they actually started digging, but then the city became insolvent. This is the third time.

Of the four line cuts being mentioned, all are overlapping ones - that is the parts that would be cut go along the route of another line. One is a local that doesn't run nights or weekends, presumably the parallel express would now run local all the way - a major pain for those living way out in Queens. One is a skip-stop rush hour service - i.e. the two lines each do alternate stops to make for faster travel, one is useful since it reaches large chunks of South Brooklyn from the Financial District, while it's overlapping line turns off into Brooklyn a bit further north, the third one is the only line not to touch Manhattan, and as such has long been the stepchild of the system, but it is very useful for getting around between points within Brooklyn or from Brooklyn to Queens. The part which they want to shut down runs within Queens and isn't that big a deal - it already only runs nights and weekends.