Jishnu;
Got any numbers for Grand Central Station just for comparison ?
Not off the top of my head.
One thing is clear though that after ESA opens NYP and GCT will become much closer in ridership numbers. MTA projects that by 2020 LIRR net ridership will go up 96,000 to 323,000, and of that about 162,000 will go to GCT. Now with ARC not happening at NYP, ridership on Amtrak and NJT will probably not increase enough to fill the ridership that moves to GCT, so all in all NYP will be decongested at least as far as pedestrian traffic goes, and GCT and the west side subway lines will become far worse, which is hard to imagine for the Lex subway.