I just can't see rail conquering the terrain without massive capital investment, and the money would likely be better spent elsewhere where we'd get more bang for our buck. For Rockland<>Westchester<>Fairfield transportation, enhanced bus service (BRT/dedicated lanes) seems like the only reasonable answer. However, I'd be remiss to ignore the desire to connect Rockland/Orange with Manhattan. PABT and the XBL are both maxed out, and the plan to simply expand or build a larger PABT are just band-aid solutions that don't address the problem at its root cause, that being the sheer volume of people riding in. It would be worth it to study the daily ridership into the PABT or even on all routes using the XBL (since many just go onto local streets rather than into the PABT) to see which have passenger volumes that would justify replacing them with commuter rail service. I'm willing to bet a lot of Hoboken division routes (PVL, Bergen/Main, Port Jervis) and areas along rail lines that don't have any commuter rail are heavy contributors and could justify direct commuter rail into Manhattan. Gateway doesn't solve it without the Secaucus loop, and even then Gateway would probably get maxed out with beefing up the existing Amtrak/Midtown Direct/NEC/NJCL/RVL services, so no space for the Hoboken division stuff (and that's assuming the necessary Penn South completion as well). That being said, what about using the old Edgewater tunnel as a lead to start diving down into a new tunnel that would hook into the Empire Connection? With Penn South, space could perhaps be freed up on the existing NYP tracks 1-5 for WOH services. The limiting factor here would be the single track connection from 42ndish St to NYP (could a second track be strung under all the new Hudson Yards development?).
To the ones that will automatically say no, we can't build another tunnel, the only response I have is what other choice is there to get the job done? Our infrastructure expansion has not kept up with our regions growth, so now we're stuck scrambling to get everything done all at once in order to catch up.